These Old Fashioned Rhubarb Bars are a delicious way to celebrate rhubarb season. A buttery shortbread crust is topped with tangy rhubarb and a sweet custard filling for a nostalgic treat everyone will love.

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“Made it exactly as printed and turned out perfect. It was gone in 24 hours. Would of been sooner if I had to tell everyone to back off, you have to wait till it has cooled down. I am baking another one now.” -Kathrine

Every year, I get SO excited for rhubarb season. I usually make a big pot of Rhubarb Sauce and then a Rhubarb Cake for snacking in the afternoons. This year, I tried a new-to-me recipe that I’ve deemed the BEST Rhubarb Bars ever! Because, oh my goodness, are they good.
I’ve seen this recipe in a variety of church cookbooks, so this seems to be “THE” old fashioned rhubarb bar recipe. They are also known as Rhubarb Dream Bars.
It starts with a shortbread crust, then a sweet and tangy rhubarb topping, which creates a custard-like filling. They’re really similar to a Classic Lemon Bar, but with rhubarb added. Hope you love these as much as I did!
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Tips for making the best rhubarb bars
- Do not to remove the bars from the oven too soon. They should not move at all in the middle when you jiggle the pan. If the middle is still runny, return the pan to the oven for 5 more minutes, then check again.
- I don’t recommend making these with frozen rhubarb. Frozen rhubarb will add too much moisture to the recipe, making them runny.
- Leave time for the bars to chill in the refrigerator before slicing. This will also firm up the filling.
Ingredients
- The star of the show is fresh rhubarb. You’ll need 4–6 stalks, depending on the size of each stalk. Have extra after making this? Try this Old Fashioned Rhubarb Crumble next!
- The shortbread crust is buttery and flaky. We’ll use flour and butter to create the flakiness, and powdered sugar to sweeten it.
- The filling is made of sugar, eggs, flour, and cornstarch. It creates a sweet custard that complements that tart rhubarb nicely. The cornstarch is not true to the “original” recipe, but I found it needs a bit of it for the filling to firm up nicely.
How to Make Old Fashioned Rhubarb Bars
- Cut a stick of butter into small cubes, then work the cubes into the flour and powdered sugar. You can use a fork, a pastry blender, or your hands.
- Pat it into an 8×8-inch dish and bake for 15 minutes at 350°F.
- Chop the rhubarb into one-quarter inch pieces.
- Mix the flour, sugar, cornstarch, eggs, and rhubarb. Pour over the crust and bake for about 40 minutes, or until it no longer jiggles in the center.
Let the rhubarb bars cool completely before cutting.
Variations
Rhubarb Bars are easily customizable! Here are a few ideas:
- Add the zest of one lemon to the filling OR the crust (before baking)
- Stir in the zest of one orange to the filling OR the crust (before baking)
- Stir in ¼ teaspoon ground cinnamon to the filling before baking
- Dust the tops of the rhubarb bars lightly with powdered sugar after cooling
📖 Recipe
The Best Rhubarb Bars
Ingredients
For the crust:
- 1 cup flour
- 5 tablespoons powdered sugar
- ½ cup cold butter, diced
For the filling:
- ¼ cup flour
- 1 cup granulated sugar
- 1 tablespoon cornstarch
- ¾ teaspoon salt
- 2 eggs, beaten
- 2 cups chopped rhubarb
Instructions
- Preheat oven to 350°F. Grease an 8×8 inch baking dish with cooking spray.
- Whisk 1 cup of flour and the powdered sugar in a large bowl.1 cup flour, 5 tablespoons powdered sugar
- Using your fingers, a fork, or a pastry blender, cut the butter into the flour mixture, similar to making a pie crust. The butter should be the size of small peas and the dough should stick together when pressed together.½ cup cold butter,
- Pour the dough into the baking dish and pat down into an even layer. Bake for 15 minutes.
- Meanwhile, whisk together the remaining ¼ cup flour, sugar, cornstarch, and salt. Gently stir in the beaten eggs and the chopped rhubarb. Only stir JUST until combined.¼ cup flour, 1 cup granulated sugar, 1 tablespoon cornstarch, ¾ teaspoon salt, 2 eggs,, 2 cups chopped rhubarb
- Pour the mixture into the baked crust, and bake for another 38–45 minutes. The center should not move at all when you jostle the pan.
- Let cool completely before cutting into bars. For best results, refrigerate for several hours before cutting.
Could you make the crust..freeze it for a few days then thaw it and finish the recipe later?
I haven’t tried it but I suspect that you could.
Delicious!
I’m so glad you enjoyed them! Thanks for taking the time to comment.
Made it exactly as printed and turned out perfect. Mine took 43 minutes. I took it out at 38 minutes but still had a bit of a jiggle so I put it in for 5 more minutes. It was gone in 24 hours. Would of been sooner if I had to tell everyone to back off, you have to wait till it has cooled down. I am baking another one now. I will post a pic if I can. I did forget to grease my pan this time and I had roughly a cup of left over fruit so I mixed it with the rhubarb. I hope it works out. Question, I saw you can double and triple the recipe. It didn’t change the size of the pan?
I’m so glad these turned out well for you! If you double the recipe, use a 13×9-inch pan. If you triple it, use one 13×9-inch pan and one 8×8-inch pan. Thank you for taking the time to leave a review!