Simple yet delicious rhubarb bars with a buttery shortbread crust, sweet and tart rhubarb custard filling, and finished with a cinnamon oatmeal streusel topping. All you could ever want in a rhubarb bar! Plus, they're so easy to make!
When creating these rhubarb bars, I wanted them to include all the best things! A thick and buttery crust that would hold up to all the filling, a rhubarb center that isn't overly sweet, and a streusel crumble topping because no bar is truly complete without it. And these bars are just that - perfection!
I could eat these rhubarb shortbread bars for breakfast, lunch, and dinner.
If you're looking to mix things up, turn these into strawberry rhubarb bars by swapping a cup of rhubarb for sliced strawberries! Or you could even use raspberries.
You also absolutely have to make my perfect Strawberry Rhubarb Crisp with Brown Butter Streusel!! The brown butter adds SO much flavor! It's insane.
Why you'll love these rhubarb bars
- Easy to make. All you need is about 15 minutes of hands-on prep time to make these deliciously sweet and tart rhubarb bars!
- Shortbread crust. Made with a simple but tasty shortbread crust that's firm enough to hold up to all that tasty rhubarb filling.
- Custard rhubarb center. Soft, sweet, and tart rhubarb custard filling that requires minimal ingredients and is quickly mixed up in a bowl - no stovetop cooking!
- Crumble topping. In my opinion, a good bar is always finished with a sweet oatmeal streusel crumble. The final component making these the perfect rhubarb bars!
How to make rhubarb crumble bars
Making rhubarb bars is a 3 part process that only takes about 15 minutes! I like to use the same bowl to make the crust and filling to save on cleanup.
Scroll down to the recipe card for full instructions.
- Step 1: Shortbread crust. Whisk together the flour, powdered sugar, and salt. Pour in the melted butter and mix until combined. Sprinkle the dough into your lined baking dish and press down into an even layer. Bake for about 10-12 minutes or until a light golden color.
- Step 2: Rhubarb filling. Whisk together the sugar, flour, and salt. Add in the eggs and heavy whipping cream, then whisk until combined. Stir in the rhubarb and pour over the crust. Bake for 20 minutes.
- Step 3: Crumble topping. Mix the flour, oats, and brown sugar. Add the cold butter and use a pastry blender to work the butter into the mixture until combined but crumbly. Remove the bars from the oven and sprinkle the crumble over the rhubarb filling. If desired, top with some extra slices of rhubarb.
- Step 4: Bake. Continue to bake for another 25-30 minutes until the filling is set and no longer jiggly. Let cool for 30-60 minutes then cover and refrigerate to cool completely before slicing into bars.
Substitutions and variations
- To make the bars more tart. I feel like these bars are the perfect balance between sweet and tart, but if you prefer a more tart rhubarb filling, increase the amount of rhubarb to 3 or 3 ½ cups or decrease the sugar to ¾ cup.
- Add fruit. To make strawberry rhubarb bars, swap 1 cup of rhubarb for 1 cup of sliced strawberries, or even raspberries.
- Using frozen rhubarb. Frozen rhubarb contains quite a bit of liquid, so be sure to thaw and drain it first.
- Double the recipe for a 9x13-inch baking dish. Making bars for a crowd? Just double the recipe and use a 9x13-inch baking dish. The cook time will stay relatively the same. Bake the bars until the center is set and no longer jiggly.
- Make it look pretty. After you sprinkle the streusel crumble over the bars, you can also sprinkle on some slices of rhubarb that will bake into the streusel making the bars look extra pretty! Totally optional.
This recipe hasn't been tested with substitutions or variations. If you make any changes or additions, I'd love to hear how it turned out—drop a comment below!
Recipe FAQs
Strawberries are great with rhubarb! To make these strawberry rhubarb bars, swap half the rhubarb for sliced strawberries, or even raspberries. The addition of fruit adds a little extra sweetness!
No, you do not peel rhubarb. All you need to do is remove the stems. The skin actually adds a beautiful color and flavor, and it turns nice and soft after cooking.
Make ahead
Rhubarb bars can be made 1-2 days in advance and stored in the refrigerator.
How to store and freeze
- Cover and store in the refrigerator for up to 4-5 days.
- To freeze, let cool completely then slice into squares. Store in an airtight container in the freezer for up to 3-4 months. Thaw in the refrigerator.
Did you try this recipe?
I'd love to hear from you! Leave a ⭐️⭐️⭐️⭐️⭐️ rating and comment below. I appreciate your helpful feedback! Follow me on Instagram, TikTok, Facebook and Pinterest for more delicious recipes!
Thanks so much! - Rachel
Rhubarb Shortbread Crumble Bars
Equipment
- 8x8 inch baking dish (or double the recipe for a 9x13)
Ingredients
Shortbread crust
- 1 ¼ cups all-purpose flour
- ⅓ cup powdered sugar
- ⅛ teaspoon salt
- 6 tablespoons salted butter, melted
Rhubarb custard filling
- 1 cup granulated sugar
- ¼ cup all-purpose flour
- ⅛ teaspoon salt
- 2 eggs
- ¼ cup heavy whipping cream
- 2 ½-3 cups rhubarb chopped
- 1 teaspoon vanilla extract
Crumble topping
- ¼ cup all-purpose flour
- ¼ cup old fashioned oats
- ¼ cup brown sugar packed
- ¼ teaspoon baking powder
- ¼ teaspoon cinnamon
- ¼ cup cold salted butter cubed
Instructions
- Heat oven to 350°F and line an 8x8 inch baking dish with parchment paper.
- Whisk together the flour, powdered sugar, and salt. Pour in the melted butter and mix until combined. Sprinkle the dough into your lined baking dish and press down into an even layer. Bake for about 10-12 minutes or until a light golden color.
- While the crust bakes, make the filling. In a large bowl, whisk together the sugar, flour, and salt. Add in the eggs and heavy whipping cream, then whisk until combined. Stir in the rhubarb and pour over the crust. Bake for 25 minutes - the filling will finish baking after you add the streusel.
- Meanwhile, make the crumble topping. In a small bowl, whisk together the flour, oats, and brown sugar. Add the cold butter and use a pastry blender to work the butter into the mixture until combined but crumbly - store in the fridge to keep cool until it's time to sprinkle over the bars. Evenly spread the crumble over the rhubarb filling. If desired, top with some extra slices of rhubarb.
- Continue to bake for another 20-25 minutes until the filling is set and no longer jiggly.
- Let cool for 30-60 minutes then cover and refrigerate to cool completely before slicing into bars.
Notes
- To make the bars more tart. I feel like these bars are the perfect balance between sweet and tart, but if you prefer a more tart rhubarb filling, increase the amount of rhubarb to 3 or 3 ½ cups or decrease the sugar to ¾ cup.
- Add fruit. To make strawberry rhubarb bars, swap 1 cup of rhubarb for 1 cup of sliced strawberries, or even raspberries.
- Using frozen rhubarb. Frozen rhubarb contains quite a bit of liquid, so be sure to thaw and drain it first.
- Double the recipe for a 9x13-inch baking dish. Making bars for a crowd? Just double the recipe and use a 9x13-inch baking dish. The cook time will stay relatively the same. Bake the bars until the center is set and no longer jiggly.
- Make it look pretty. After you sprinkle the streusel crumble over the bars, you can also sprinkle on some slices of rhubarb that will bake into the streusel making the bars look extra pretty! Totally optional.
Nutrition
Nutritional information is automatically calculated by a third party software and is only an estimate, not a guarantee. This information is provided as a courtesy, and you are solely responsible for all decisions related to your health.
Megan
Delicious bars! I loved that they were easy to cut and didn't get soggy.
Modern Farmhouse Eats
Megan, I'm so glad you enjoyed the recipe! Thanks so much for leaving a review!
Wanda
There are ingredients listed in the recipe that are not mentioned in the directions.
Kelly
Step #4 says combine granulated sugar and brown sugar for crumble topping, but there is no quantity listed for granulated sugar under the crumble ingredients.
Modern Farmhouse Eats
Kelly, there's actually just brown sugar in the crumble topping. Thank you for bringing that to my attention!