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Easy Rhubarb Bars Recipe with Oatmeal

Make rhubarb oatmeal bars for a sweet and tart treat featuring spring’s first fruits!

With a hearty oat crust and slightly sweet, tart rhubarb filling, these rhubarb crumble bars have something for everyone.

Simple to bake and a delight to eat these old-fashioned rhubarb bars are ideal for weeknight dessert, potlucks, and more.

If you have homemade canned rhubarb pie filling in your pantry or freezer, this is a great recipe to use up a quart. If you don’t, there’s a recipe for making the bard with fresh rhubarb below.

An oat topped dessert bar sitting on a plate with a fork and napkin, the remaining pan of bars in the background. A text overlay reads: rhubarb oatmeal bars.

Staple Ingredients

The great thing about this recipe is that once you have rhubarb harvested from the garden or purchased from the farmer’s market, you likely already have all the other ingredients on hand making it quick to pull together. Here are a few tips to keep in mind.

Self-Rising Flour

The crust uses self-rising flour for ease. It provides plenty of lift to the crust without making it too puffy and keeping a slight crunch.

If you don’t have self-rising flour, make your own by mixing together 1 1/2 cups all purpose flour, 2 1/4 teaspoons baking powder and a generous 1/4 teaspoon of salt. That will work in the same fashion for you.


Use rolled oats for a heartier texture in the crust. Quick oats or instant could likely work but won’t have the same texture to them.

Brown Sugar

The brown sugar in the crust provides for a great depth of flavor and perfect balance to the tartness in the the filling. I’ve made the bars with both light and dark brown types – even a combination when I didn’t have a full cup of dark brown sugar on hand. Use whatever you have in the pantry or prefer. If you only have white sugar, it will stiff work but the crust will won’t be as flavorful and it will be more crumbly.


For the filling, you will need 3 full cups diced rhubarb. Dice it small for a smoother filling, a larger chop will keep some chunks in the bars.

Save a bit of time, if desired, dice the rhubarb the day before and keep stored in a sealed container in the refrigerator.

When ready to bake, just pull the rhubarb from the fridge and proceed with the recipe.

rhubarb stalks at farmers market

Substitute Canned Pie Filling

While you can make the filling fresh in spring, if rhubarb season has passed use a quart jar of frozen or canned rhubarb pie filling instead. This makes for a batch of super easy rhubarb bars. 

A full pan of rhubarb oatmeal bars as seen from above with a glass jar of rhubarb pie filling sitting next to it.

Using Frozen Rhubarb

If you have slices of frozen rhubarb in the freezer, let it thaw and drain the excess water. Then proceed with cooking the filling as described in the full recipe below.

Other Options

Use any pie filling you have on hand, strawberry rhubarb bars would be quite nice. Homemade jam would also work but provide slightly different texture.

After spreading the filling on the crust, top it with some chocolate or white chocolate chips. Then finish by crumbling on the top crust and bake.

Adding up to 1/2 cup of finely chopped nuts to the flour mixture s a great way to add an extra crunch to these bars. 

Drizzle the baked and cooled bars with some melted chocolate.

A simple vanilla powdered sugar glaze, drizzled over the baked bars is lovely and tasty, too!

A rhubarb oatmeal bar on a white plate with a fork and napkin with remaining pan full in the background.

How to Serve

There’s no real reason to get fancy here. This is intentionally a rustic, old-fashioned dessert designed to highlight the garden harvest. Keep it simple:

Cut the bars with a sharp knife and serve with coffee or tea as desired for a light snack or even brunch.

Add a dollop of whipped cream or scoop of vanilla ice cream for an even more delicious dessert.

Dust the cut and plated bars with just a bit of powdered sugar right before serving for added color and eye-catching appeal.

A rhubarb oatmeal bar sitting on a white plate with a fork and napkin next to it.

How to Store

Keep leftovers in an airtight container in the refrigerator for up to 5 days.

For longer term storage, freeze the bars. Simply cut the bars and put into freezer bags and freeze solid.

Let frozen bars thaw in the refrigerator prior to serving. Eat up frozen bars within six months for optimum freshness and flavor.

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Yield: 16 Servings

Oatmeal Rhubarb Bars

A rhubarb oatmeal bar on a plate with a fork.

Make old-fashioned rhubarb oatmeal bars for the rhubarb lover in your life. These tart but sweet rhubarb bars are the perfect dessert for spring and early summer. 

Prep Time 20 minutes
Cook Time 35 minutes
Total Time 55 minutes



  • 2 Cups Rolled Oats
  • 1 Cup Brown Sugar, lightly packed
  • 1 1/2 Cups Self-Rising Flour
  • 1 Cup Salted Butter, softened to room temperature**

Rhubarb Filling

  • 3 Cups Rhubarb, diced
  • 3/4 Cup Sugar
  • 2 Tablespoons Cornstarch
  • 1/4 Cup Cold Water
  • 1 teaspoon Vanilla Extract


  1. Preheat the oven to 350 degrees Fahrenheit.
  2. Grease a 9X13" baking dish. (or line bottom of the pan with parchment paper)

Make the Filling:*

  1. In a saucepan, combine the rhubarb, sugar, cornstarch, and water.
  2. Simmer over medium heat, stirring frequently until it thickens and the liquid becomes clear.
  3. Remove from heat, stir in the vanilla. Set aside.

Make the Crust

  1. Mix all the ingredients together in a medium mixing bowl until crumbly. This mixes together quite easily with a for but you could also use a hand mixer on low or a pastry blender.
  2. Press 2/3 of the mixture evenly into the bottom of the prepared pan. 
  3. Spread the rhubarb mixture in an even layer over the bottom crust.
  4. Top the filling with the remaining crust, by crumbling bits of the oat mixture over the top. This will create a crumble topping without any extra work. 
  5. Bake in the preheated oven for 30-35 minutes, or until crust is golden brown and filling is bubbling.
  6. Let pan cool on a wire rack.
  7. When cool, slice and serve.
  8. Store leftovers in the refrigerator.


*Use a quart car of rhubarb pie filling instead of making the filling, if desired.

**If using unsalted butter, add 1/4 tsp salt to crust ingredients.

Nutrition Information:



Serving Size:


Amount Per Serving: Calories: 271Total Fat: 12gSaturated Fat: 7gTrans Fat: 0gUnsaturated Fat: 4gCholesterol: 31mgSodium: 236mgCarbohydrates: 38gFiber: 2gSugar: 21gProtein: 3g

We try our best but cannot guarantee the accuracy of this nutrition information.

More Rhubarb Recipes

Whether you growing rhubarb on your property or are buying rhubarb at your local farmer’s market, make the most of rhubarb season with these delicious rhubarb recipes.

Balsamic Strawberry Rhubarb Jam

Preserving Rhubarb

Rhubarb Crisp

Thanks for sharing!

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