Bars + Brownies Pies + Tarts Spring Summer

Raspberry Rhubarb Streusel Pie Bars

rhubarb pie bars in a cast iron baking pan
rhubarb bars on a plate with a dollop of whipped cream

Raspberry Rhubarb Streusel Pie Bars are the perfect introduction to Spring baking. I love the sweet-tart, jammy filling with the buttery press-in crust, and oat streusel topping that adds a nice crunch.

This post is sponsored by Lodge Cast Iron, and I’ve used their Casserole Pan to make the pie bars, which ensures a crisp crust and even baking, and the handles make it easy to get the pan in and out of the oven. Plus it’s highly versatile and lasts forever! 

More Rhubarb Recipes:

raspberry rhubarb pie bars on plate

Raspberry Rhubarb Pie Bars

Servings: 16 bars
Prep Time: 30 minutes
Cook Time: 55 minutes
These raspberry rhubarb pie bars are easy to make with a press-in crust, and sweet-tart, jammy filling. Topped with an oat streusel for crunch.
Sarah Kieffer
5 from 3 votes
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  • 2 ½ cup [355 g] all-purpose flour
  • ½ cup [45 g] rolled oats
  • ½ cup [100 g] granulated sugar
  • ½ cup [100 g] brown sugar
  • ½ teaspoon baking soda
  • ½ teaspoon salt
  • 1 cup [2 sticks or 227 g] unsalted butter at room temperature, sliced into 1 in [2.5 cm] pieces


  • 2/3 cup [130 g] granulated sugar
  • ¼ cup [28 g] cornstarch
  • ¾ teaspoon ground cinnamon
  • ¼ teaspoon salt
  • 16 oz [454 g] rhubarb fresh or frozen, chopped into 1 in [2.5 cm] pieces 12 oz [368 g] raspberries, fresh or frozen
  • 1 teaspoon pure vanilla extract


For the crust

  • Adjust an oven rack to the middle of the oven. Preheat the oven to 350F [180C]. Grease a 9 x 13 in [22 by 33 cm] Lodge cast iron casserole pan and line it with a parchment sling.
  • In the bowl of a stand mixer fitted with a paddle, mix the flour, oats, granulated and brown sugars, baking soda, salt, on low speed to combine. Then add the butter and mix on medium-low speed until the mixture resembles coarse sand.
  • Press half of the flour mixture into the bottom of the prepared pan. Bake for 10 minutes. Prepare the filling while the crust is baking.

For the filling

  • In a small bowl, whisk together the granulated sugar, cornstarch, cinnamon, and salt.
  • In a large bowl, mix the rhubarb, berries, and vanilla together. Pour the sugar mixture over the fruit and stir gently with a spatula to evenly combine.

To assemble

  • Remove the pan from the oven, spread the filling over the crust in an even layer, and sprinkle the remaining crust mixture evenly over the top. Bake for 50 to 60 minutes, until the crumbly top is light golden brown and the fruit juices have started to bubble. Transfer the pan to a wire rack to cool. Place the pan in the fridge and let the bars chill for 4 to 6 hours. Slice the bars and serve, serve with whipped cream if desired. Bars can be served cold or at room temperature and will keep in the fridge for up to 2 days.
  • Reply
    Wednesday, May 18, 2022 at 5:22 am

    5 stars
    Just soo excited for making these with my kid!!!

  • Reply
    Wednesday, May 4, 2022 at 9:55 pm

    5 stars
    Hi! I love your recipes and especially your bar recipes from your 100 cookies book. Turned out amazing! Huge hit!! Thank you!

  • Reply
    Saturday, April 30, 2022 at 11:17 am

    5 stars
    Absolutely delicious!

  • Reply
    Connie Douglas
    Tuesday, April 26, 2022 at 1:36 pm

    I see the 1 cup butter in the ingredients, but it doesn’t say when to add it, I presume with the other crust ingredients in mixer bowl? Thanks, looks great!

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