Tart, jammy, and wrapped in a golden oat crumble—these Rhubarb Oat Bars are the kind of dessert that quietly surprises you, then hooks you for good. Inspired by rustic European cafés and Midwest potlucks, they blend bold flavor with humble ingredients in the best way.
The sweet-tart rhubarb compote melts into a buttery base, creating layers of texture and nostalgia. And honestly, it tastes just as good as our other dessert recipes like Chocolate Coffee Cake and Mini Cookies—only with a tangy twist that stands out.
Whether you’re new to rhubarb or already a fan, this recipe teaches you to embrace its brightness and balance. It’s the kind of bake that invites curiosity—and leaves you with a new favorite in your rotation.
What Makes This Recipe Special?
- I stumbled into making this while trying to use up farmers market rhubarb—now I stock up just to bake it again every spring.
- It’s perfect for sharing, but honestly? I’ve eaten half the pan with my morning coffee—warm or chilled, it’s addictive.
- I’ve swapped in strawberries, apples, even ginger once—each version taught me how versatile this oat crust can be.
- It’s unexpectedly light and satisfying, and cutting refined sugar a bit didn’t hurt the flavor one bit—felt indulgent without the guilt.
- The taste? Bright, buttery, and beautifully balanced—comforting yet fresh in every bite.
Rhubarb Oat Bars Recipe
These sweet-tart rhubarb oat bars combine a buttery crumble crust with a gooey rhubarb filling, perfect for spring and summer. With a chewy texture and golden topping, they’re simple to make and perfect for picnics, potlucks, or a rustic dessert with coffee.
Equipment
- 13×9-inch baking pan
- Mixing bowls
- Measuring cups
- Measuring spoons
- Saucepan
- Wooden spoon or silicone spatula
- Oven mitts
Ingredients
Crust
- 1 cup brown sugar packed
- 1½ cups flour
- ¼ teaspoon vanilla
- ½ cup chopped nuts
- 1½ cups rolled oats
- ¼ teaspoon salt
- 1 cup shortening
Filling
- 1½ cups sugar
- 1 teaspoon vanilla
- 2 tablespoons cornstarch
- 3 cups chopped rhubarb
- ¼ cup water
Instructions
- Preheat the oven to 350°F.
- In a large mixing bowl, combine the crust ingredients and mix until crumbly.
- Press half of this mixture evenly into a 13×9-inch baking pan and bake for about 20 minutes.
- While the crust is baking, place the rhubarb, sugar, cornstarch, and water in a saucepan and cook over medium heat, stirring constantly, until the mixture becomes clear and thick.
- Remove from heat and stir in the vanilla extract.
- Once the crust is baked, pour the rhubarb filling evenly over it.
- Sprinkle the remaining crumb mixture on top and return to the oven to bake for another 20 minutes, until the top is golden and the filling is bubbling.
- Let cool completely before cutting into bars.
Notes
- Rolled oats give a heartier texture, while quick oats create a finer crumble—choose based on preference.
- To easily press the crust into the pan, use the flat bottom of a measuring cup.
| Calories | 229.7kcal |
| Carbohydrates | 32.9g |
| Fiber | 1.3g |
| Fat | 10.4g |
| Protein | 2.1g |
Tips To Ease Your Job!
- Prep Your Ingredients First: Chop the rhubarb, measure out the oats, sugar, and cornstarch before starting. Having everything ready will make the process smooth and stress-free.
- Line the Pan with Parchment Paper: This makes it much easier to lift out the bars after baking and ensures clean, easy slicing.
- Use Cold Butter for the Crumble: Cold, diced butter creates that perfect crumbly texture. You can even use a pastry cutter or your fingertips for quick mixing.
- Stir Filling Constantly: To prevent lumps or burning, stir the rhubarb filling non-stop until it turns clear and thickens—this ensures a smooth, glossy layer.
