Rhubarb Oatmeal Bars: Perfect Blend of Rhubarb and Oats!

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These rhubarb oatmeal bars are made with a luscious rhubarb filling, nestled between layers of hearty oat crust and topping. It’s the perfect way to celebrate the seasonal delight of rhubarb in a simple and irresistible dessert. And if you’re looking for another rhubarb recipe, be sure to check out this rhubarb banana bread. It’s a delicious twist on a classic banana bread recipe that’s perfect for springtime baking.

close up view of baked rhubarb bars on a white plate.

With rhubarb season in full swing, you’ll discover the vibrant stalks at your local farmer’s market, just waiting to be transformed into a delicious treat. And my personal favorite rhubarb recipe? This irresistible Rhubarb Oatmeal Bars. What I love about these bars is that they capture the delightful flavor of rhubarb while resembling the taste of a pie, without the hassle of pie-making.

WHY YOU’LL LOVE THIS RECIPE

Wholesome Ingredients: This recipe embraces the use of wholesome ingredients, such as oats and fresh rhubarb. Oats are known for their nutritional benefits, including being a good source of fiber. Fresh rhubarb adds a burst of vitamins and minerals to the bars. By indulging in these rhubarb oatmeal bars, you can enjoy a delicious treat while also incorporating some nourishing elements.
Versatile and Easy to Make: Rhubarb oatmeal bars are not only delicious but also versatile and easy to prepare. The recipe allows for customization, giving you the opportunity to add your own personal touch. Plus, the straightforward instructions make this recipe accessible to both experienced bakers and beginners.
Perfect for Seasonal Baking: Rhubarb is often available during the spring season, and incorporating it into oatmeal bars is a fantastic way to embrace seasonal produce and add a unique twist to a classic recipe.
Perfect for Any Occasion: Whether you’re hosting a gathering, treating yourself to a cozy dessert, or looking for a sweet addition to your brunch menu, rhubarb oatmeal bars fit the bill. These bars are versatile enough to be enjoyed as a snack or a dessert, making them a delightful addition to any occasion. I included these in a dessert tray for my son’s 8th birthday party!

INGREDIENTS YOU’LL NEED

Overhead view of rhubarb oatmeal bar ingredients.

Fresh Rhubarb: Rhubarb adds a unique tartness and vibrant flavor to the oatmeal bars. Its tangy taste beautifully contrasts with the sweetness of the other ingredients, creating a delicious balance of flavors.
Oats: Oats provide a hearty and wholesome texture to the bars. They add a chewy consistency and nutty flavor, making the bars more satisfying and adding depth to each bite. I prefer the flavor and chewiness of old-fashioned rolled oats, but quick oats can be substituted to yield softer, cakier bars. Do not use instant oats.
Cinnamon: Cinnamon is a warm and aromatic spice that complements the flavors of rhubarb and oats. Its presence enhances the overall taste profile, adding a comforting and subtly sweet note to the bars.
Brown sugar: Brown sugar lends a rich sweetness to the bars, enhancing the natural flavors of the rhubarb and creating a caramel-like undertone. It contributes to the overall indulgence and depth of flavor in each bite.
Unsalted Butter: Butter is essential for creating a moist and buttery texture in the oatmeal bars. It adds richness and depth of flavor, resulting in a melt-in-your-mouth experience. I use unsalted butter so I can control the salt.
All-purpose flour: All-purpose flour is used as the base ingredient in the crust and streusel topping of the oatmeal bars. It provides structure and helps bind the ingredients together, resulting in a firm and cohesive texture. I like using the Gold Medal brand. Gold Medal yields a mid-range protein level of around 10 to 11%—perfect for a wide variety of baked goods.
Salt: Salt is a crucial ingredient that enhances the overall flavor profile. It balances the sweetness, enhances other flavors, and adds depth to the taste. Even a small amount of salt can make a significant difference in bringing out the flavors of the rhubarb and other ingredients. I use Diamond Crystal salt.
Slivered Almonds: Slivered almonds add a delightful crunch and nutty flavor to the bars, complementing the soft texture of the rhubarb and oats.
Vanilla: Vanilla extract is a common flavoring used in baking to add depth and enhance the overall taste of the bars. It imparts a warm and aromatic note that complements the sweetness of the bars.

HOW TO CUT RHUBARB

Rinse the rhubarb stalks: Start by rinsing the rhubarb stalks under cold water to remove any dirt or debris. Pat them dry with a clean kitchen towel.
Remove any leaves: Although rhubarb leaves may seem harmless, they actually contain toxic chemicals that can be harmful to both humans and animals. While it would require consuming a significant amount to cause illness, it is highly recommended to avoid consuming them altogether for safety reasons.
Trim the ends: Trim off the ends of the rhubarb stalks using a sharp knife. Discard any tough or woody parts.
Cut into manageable lengths: If the rhubarb stalks are long, cut them into more manageable lengths, typically around 4-6 inches long. This will make it easier to handle and slice.
Slice into thin strips: Take one rhubarb stalk at a time and hold it firmly on a cutting board. Use a sharp knife to slice the stalk lengthwise into thin strips, approximately 1/4 to 1/2 inch wide.
Dice into cubes: Once you have the thin strips, gather them together and cut across the strips to create small cubes. The size of the cubes can vary depending on your preference, but aim for uniform pieces to ensure even cooking.
Repeat with remaining stalks: Repeat the slicing and dicing process with the remaining rhubarb stalks until you have the 2 cups of cubed rhubarb.

You will need approximately 2-3 stalks for this recipe depending on the size.

overhead view of a rhubarb stalk being cut with a knife down the center of the stalk.

overhead view of rhubarb stalks on a cutting board being cut with a knife into cubes.

HOW TO LINE A PAN WITH PARCHMENT PAPER

Here are the instructions on how to line a pan with parchment paper and cooking spray:

Measure and cut the parchment paper: Begin with a square of parchment paper that is at least one inch larger than your pan on all sides. Place your pan in the center of the paper and use it as a guide.
Cut the corners: Cut out a small square from each corner of the parchment paper. This will allow the paper to fit neatly into the pan without overlapping or bunching up.
Grease the pan and place the parchment paper: Lightly grease the inside of your pan using cooking spray or a small amount of oil. Carefully place the cut parchment paper into the pan, ensuring that it covers the bottom and sides. Press it down gently into the greased pan to help it adhere.
Grease the parchment paper: To further prevent sticking, lightly grease the parchment paper. This step will make it easier to remove your baked goods from the pan once they are done.
By following these steps, you’ll have a well-lined pan that will make baking and releasing your treats a breeze. Enjoy your delicious creations with easy cleanup!

The image shows an empty metal baking pan placed on top of parchment paper, which is on a marble countertop. The parchment paper beneath it appears to be cut to fit the pan, possibly in preparation for baking. The perspective is from above, providing a clear view of the pan and the parchment setup.

The image depicts a salt shaker tipped to the side with salt grains spilling out from its opening. The background is plain, highlighting the salt shaker as the focal point. The style is simplistic, using a limited color palette, and the image appears to be a vector or digital illustration rather than a photograph.

Sarah’s Pro Tip

If your variety of rhubarb doesn’t cook down into a pretty shade of pink, you can add a handful of raspberries or add a drop of pink food coloring to the rhubarb mixture. I added a drop of pink food coloring to the recipe pictured here.

HOW TO MAKE RHUBARB OATMEAL BARS

STEP 1: Combine rhubarb, granulated sugar, and water in a small saucepan. Heat over low heat, stirring occasionally, until the rhubarb has broken down and it is slightly thickened. This will take 12 -15 minutes. Remove from heat and allow to cool for 30 minutes.

overhead view of chopped rhubarb and sugar in a saucepan.

overheard view of rhubarb cooked down in saucepan.

STEP 2: Whisk oats, flour, cinnamon, and salt together in a medium-sized bowl.

overhead view of dry ingredients piled into glass bowl.

Overhead view of dry ingredients mixed in a glass bowl.

STEP 3: Using a stand mixer fitted with the paddle attachment beat the butter and brown sugar on medium-high speed until light and fluffy, about 3 minutes. Scrape down the sides of the bowl as needed. Make sure your butter is at room temperature for proper incorporation.

overheard view of a stick of butter and brown sugar in a mixing bowl.

overhead view of butter sugar and egg mixed in the mixer bowl.

STEP 4: Add the egg and vanilla and beat until combined. Reduce the speed to low and add the oat mixture. Mix until just combined.

overhead view of butter, brown sugar and a raw egg in the mixer bowl.

overhead view of dry ingredients added to the butter and brown sugar mixture.

Overhead view of the dough with the oats mixed in.

STEP 5: Transfer two-thirds of dough to prepared pan and press firmly into even layer. The dough will be sticky, you may want to spray your hands with cooking spray to help smooth it out.

overhead view of a scoop of the dough in the 8x8 pan with the mixing bowl in the lower left corner with a spatula in the bowl.

Overhead view of oatmeal crust pressed out in pan.

STEP 6: Spread the rhubarb mixture evenly over the crust. Mix slivered almonds into the remaining dough and sprinkle walnut-size pieces over rhubarb layer.

overheard rhubarb jam over the unbaked crust.

rhubarb oatmeal bars batter in mixing bowl with sliced almonds added.

overhead view of the rhubarb oatmeal bars with the topping on it prior to baking.

STEP 7: Bake until top is golden brown, 40 to 45 minutes. Let bars cool in pan on wire rack, about 2 hours. Using parchment, lift bars from pan. Cut into 12 pieces before serving.

an overhead view of baked oatmeal rhubarb bars.

overhead view of rhubarb oatmeal squares on white plates

RECIPE TIPS & TRICKS

This rhubarb oatmeal bars recipe is super easy to make, and I’ve got some tips to ensure it turns out amazing every time!

Choose fresh rhubarb: Look for firm and brightly colored rhubarb stalks. Avoid using rhubarb that is limp or discolored as it may affect the taste and texture of the bars.
Balance the sweetness: Adjust the amount of sugar in the recipe to balance the tartness of the rhubarb. Taste the rhubarb filling before baking and add more sugar if desired.
Create a sturdy crust: Press the oatmeal crust firmly into the baking dish to create a sturdy and solid base for the bars. This will make it easier to slice and serve without crumbling.
Use parchment paper: Line the baking dish with parchment paper, leaving an overhang on the sides. This will make it easier to lift the bars out of the dish once they are cooled, resulting in cleaner and neater slices.
Cool completely before cutting: Allow the rhubarb oatmeal bars to cool completely in the baking dish before cutting into squares. This will help them set and hold their shape, resulting in cleaner slices.
Bake to perfection: Bake the bars until the crust is golden brown and the rhubarb filling is bubbling around the edges. The exact baking time may vary depending on your oven, so keep a close eye on them.
Serve with a garnish: Sprinkle a dusting of powdered sugar over the bars before serving or add a dollop of whipped cream or a scoop of vanilla ice cream.

RECIPE VARIATIONS

While this rhubarb oatmeal bars is delicious as-is, you can add other ingredients to switch up the flavor profile. Here’s some options:

Strawberry Rhubarb Oatmeal Bars: Combine the tangy rhubarb with sweet, juicy strawberries for a classic flavor combination. The strawberries add a burst of sweetness that complements the tartness of the rhubarb, resulting in a delightful twist on the original recipe.
Ginger Rhubarb Oatmeal Bars: Add a hint of warmth and spice to your rhubarb bars by incorporating finely chopped or grated fresh ginger. The ginger adds a zesty kick that beautifully complements the tartness of the rhubarb, creating a flavor profile that is both refreshing and comforting.
Raspberry Rhubarb Oatmeal Bars: Mix the bright, tangy notes of raspberries with the tartness of rhubarb for a vibrant and fruity variation. The combination of these two fruits creates a burst of flavors that will excite your taste buds and add a touch of summer to your oatmeal bars.

STORAGE TIPS

Room Temperature Storage: If you plan to consume the rhubarb oatmeal bars within a couple of days, you can store them at room temperature. Ensure that the bars are completely cooled before transferring them to an airtight container or wrapping them tightly with plastic wrap. Keep them in a cool, dry place away from direct sunlight. The bars can typically stay fresh at room temperature for up to 3-4 days.
Refrigerator Storage: If you want to extend the shelf life of your rhubarb oatmeal bars, refrigeration is a good option. Once the bars have cooled completely, place them in an airtight container or cover them tightly with plastic wrap. Store them in the refrigerator, where they can stay fresh for up to 5-7 days. This method helps maintain their texture and freshness.
Freezer Storage: To store rhubarb oatmeal bars for a longer period, freezing is an excellent option. First, ensure the bars are completely cooled. Cut them into individual squares or portion sizes if desired. Wrap each bar tightly in plastic wrap and place them in a freezer-safe container or zip-top freezer bags. Label them with the date and store in the freezer. Properly stored, the bars can last for up to 2-3 months in the freezer. When ready to enjoy, thaw the bars in the refrigerator overnight or at room temperature for a few hours.
Remember to always allow the bars to cool completely before storing to prevent condensation and maintain their texture. Additionally, make sure to use airtight containers or wrapping to prevent moisture from affecting the quality of the bars.

FAQ’S

How can I adjust the sweetness level of rhubarb oatmeal bars to suit my taste preferences without compromising the recipe’s balance?

Adjusting the sweetness level of rhubarb oatmeal bars is possible without compromising the recipe’s balance. If you prefer a sweeter taste, you can increase the amount of sugar or sweetener used in the recipe. Alternatively, you can use a sweeter variety of rhubarb or combine it with sweeter fruits like strawberries or apples. Remember to taste the rhubarb before incorporating it into the recipe to gauge its tartness and adjust accordingly.

How would your reheat rhubarb oatmeal bars?

When reheating rhubarb oatmeal bars, it is best to use a microwave or oven to maintain their texture. If using a microwave, heat them in short intervals to avoid drying them out. For the oven, preheat it to a low temperature (around 300°F or 150°C) and warm the bars for a few minutes until heated through. Reheating them in the oven may help restore some of the crispness to the oatmeal crust and topping. Remember not to overheat them to prevent excessive drying or burning.

Do I need to peel rhubarb before baking?

No, it is not necessary to peel rhubarb before baking. The skin of rhubarb is edible and softens during the baking process. However, you may choose to remove any tough or fibrous outer skin, especially if the stalks are thick or mature. Simply trim off the ends and gently pull off any strings or fibrous strands that may be present. This step is more of a personal preference and depends on the specific recipe and your texture preference.

When is rhubarb in season?

Rhubarb is typically in season during the spring months, from April to June, depending on the region. The exact timing may vary slightly depending on the climate and location. It is best to check with local farmers’ markets or grocery stores for the most accurate information on when rhubarb is available in your area.

overhead view of several baked rhubarb bar squares.

MORE RECIPES YOU WILL LOVE

I would love to hear your feedback if you give these delightful Rhubarb Oatmeal Bars a try! Share your thoughts in the comments below, and if your family enjoys them as much as mine does, don’t forget to give them a five-star ⭐️ rating! And, subscribe to our mailing list to receive more delicious recipes straight to your inbox.