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 11 votes
Print Pin Rate

Ingredients

Crust

  • 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

Filling

  • 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

Instructions

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
    Lydia
    Friday, May 26, 2023 at 7:25 pm

    5 stars
    I made these except with blueberries instead of raspberries. So good!

  • Reply
    ML
    Tuesday, May 9, 2023 at 6:52 am

    Can you use strawberries instead of raspberries or a mix of the two?

  • Reply
    Jenny
    Tuesday, May 2, 2023 at 2:26 pm

    5 stars
    This looks easy and something I can manage. If I don’t like rubarb then use same proportions total if only strawberries used?
    Thank you!

  • Reply
    Leslie
    Tuesday, May 2, 2023 at 11:06 am

    Do you need to thaw and drain the rhubarb and or raspberries if frozen? Thanks, I am planning on making this next week for my son in law. He loves rhubarb!

  • Reply
    Bean
    Sunday, August 28, 2022 at 6:15 pm

    5 stars
    We really liked these…but I did tweak the recipe a bit. As for flavor, the crust/topping is very buttery, light, and not too sweet at all. I didn’t use all the sugar in the filling because I like the tart with the sweet and to my palate it was just right. I used tapioca instead of cornstarch (less gummy) and no cinnamon or vanilla. I wanted to taste the fruit. Additionally, I used half the crust recipe, but all the fruit for the filling for a better (in my opinion) fruit to crust ratio and put it in a 10″ deep dish pie pan. It did slice – which I wasn’t sure it would do – and it did so at room temperature after it had sat for about 5 hours. We ate it with a small dollop of slightly sweetened whipped cream

    • Reply
      Wendy Smith
      Tuesday, April 18, 2023 at 11:25 am

      You are one of my new inspirations for me starting my new very tiny, Bakery/Cafe. This is so scary, and exciting for me. I love taking a great recipe, and tweaking into a new one for me! Thank You ??

  • Reply
    Julia Wallace
    Sunday, June 26, 2022 at 7:24 pm

    5 stars
    Thoughts on making this with sour cherries or blueberries?

  • Reply
    Julia Wallace
    Saturday, June 25, 2022 at 2:39 pm

    5 stars
    My new favorite rhubarb recipe! I’ve made this twice now – exactly as written, and it gets rave reviews from everyone! Just one minor change – I don’t have a 9×13 cast iron pan so I make it in a 12″ skillet.

  • Reply
    Gill
    Sunday, June 5, 2022 at 10:26 am

    5 stars
    I haven’t seen people go back for seconds or thirds for dessert in a long time, but this did the trick. Easy to make (only thing to be mindful of is the amount of time it takes to bake and chill).

    Will definitely be making this again.

    • Reply
      Sarah Kieffer
      Monday, June 6, 2022 at 9:14 am

      so glad to hear that everyone enjoyed these!

  • Reply
    Danielle
    Sunday, May 22, 2022 at 5:23 pm

    5 stars
    Made this today! absolutly divine. Just perfect, not too sweet, taste of the rhubarb and the raspberries together is just delicious. so happy I found you!

  • Reply
    carol
    Wednesday, May 18, 2022 at 5:22 am

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

  • Reply
    Elane
    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
    Sharon
    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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