Summertime means berry season — and these Mixed Berry Streusel Bars are a perfect way to celebrate it. A buttery streusel forms both the firm base and the crumbly topping, while a generous layer of sweet-tart berries sits in the middle. The bars are finished with a bright, tangy lemon glaze. I like them chilled, but they’re equally enjoyable at room temperature. For an extra treat, serve a bar with a scoop of vanilla ice cream.
Why You’ll Love These
- Quick and simple to prepare
- Buttery and sweet without feeling heavy
- Perfect for summer gatherings and potlucks
- An excellent way to use leftover or mixed berries
- Easily made dairy-free/vegan by swapping butter for a plant-based alternative
What Types of Berries Can I Use?
A mix of blueberries, raspberries, and blackberries works beautifully — I tend to use more blueberries and equal parts raspberries and blackberries. Blueberries help fill gaps so each bite is berry-filled. You can use any combination you prefer, or stick with one or two types. Aim for 2 ½ to 3 cups of berries total. Strawberries or cherries can also be used (slice them), and frozen berries are an option if you don’t thaw them first.
Ingredients
Besides fresh berries, you only need a few pantry staples. This keeps the recipe approachable and fast.
For the Bars
- Flour
- Sugar
- Baking powder
- Salt
- Butter (melted) — or a vegan substitute
- Vanilla extract
- Mixed berries (2 ½ – 3 cups total)
- Lemon juice
- Cornstarch
For the Lemon Glaze
- Powdered sugar
- Lemon juice
- Lemon extract (optional)
How to Make Mixed Berry Streusel Bars
- Make the streusel. Everything comes together in one bowl. Combine the dry ingredients, add the melted butter and vanilla, and mix until crumbly. Press a little more than half the mixture into the bottom of an 8″ x 8″ pan lined with parchment, then bake until the edges turn golden to form the base. Reserve the remaining streusel for the topping.
- Toss the berries. In a bowl, gently coat the berries with a little sugar, cornstarch, and lemon juice. The sugar balances the tartness, lemon adds brightness, and cornstarch helps thicken any juices released during baking.
- Assemble the bars. Once the streusel base has cooled slightly, spread the berry mixture evenly over it. Break the reserved streusel into small bits with your hands and sprinkle over the berries so they’re well covered, then bake until the topping is golden.
- Make the glaze. Whisk powdered sugar with lemon juice and a touch of lemon extract, if using, until smooth. The glaze should be pourable but not too thin.
- Cut, glaze, and enjoy. Allow the bars to cool completely before cutting into eight squares. Drizzle with the lemon glaze. Serve chilled or at room temperature.
How to Store the Berry Streusel Bars
Store the bars at room temperature in an airtight container for a few days, or refrigerate to keep the streusel base firmer. They’re lovely slightly chilled; keep them covered well so they don’t dry out.
More Summer Dessert Ideas
- Chantilly Crepe Cake
- Chocolate Sprinkle Cookie Ice Cream Sandwiches
- Raspberry Orange Pistachio Cake
- Caramel Cone Crunch Cookies
- Lemon Bundt Cakes
If you make these bars, please leave a comment or tag the creator on Instagram. Happy baking!
Mixed Berry Streusel Bars
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Ingredients
For the Streusel
- 2 cups (260g) all-purpose flour
- ⅔ cup (146g) granulated sugar
- ¾ teaspoon baking powder
- ¼ teaspoon salt
- ¾ cup (170g) butter, melted
- ½ teaspoon vanilla extract
For the Berries
- 1 cup (170g) fresh blueberries
- ⅔ cup (110g) fresh raspberries
- ⅔ cup (115g) fresh blackberries
- 2 Tablespoons (25g) granulated sugar
- 1 Tablespoon (14g) lemon juice
- 2 teaspoons cornstarch
For the Lemon Glaze
- ½ cup (58g) powdered sugar
- 2 teaspoons lemon juice
- ⅛ teaspoon lemon extract (optional)
Instructions
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Streusel: Preheat the oven to 350°F. Lightly grease an 8″ x 8″ square pan and line it with parchment paper, leaving an overhang on all sides.
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In a large bowl, mix flour, sugar, baking powder, and salt. Add melted butter and vanilla, stirring with a fork until the mixture becomes crumbly.
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Press a little more than half the streusel into the prepared pan, packing it firmly and evenly. Bake for 13–15 minutes or until the edges are golden. Let cool at least 10 minutes.
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Berries: In another bowl, combine the berries, granulated sugar, lemon juice, and cornstarch. Toss gently until coated. Spread the berry mixture over the cooled streusel base.
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Crumble the remaining streusel into small clumps and sprinkle evenly over the berries. Bake for 24–26 minutes, until the streusel turns golden. Let cool completely, then cut into 8 pieces.
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Glaze: Whisk powdered sugar with lemon juice and optional lemon extract until smooth. Drizzle over the cooled bars.
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Serve chilled or at room temperature. Enjoy!
Notes
- Storing: Store in an airtight container at room temperature or refrigerated.
- Berries: Use any combination totaling 2 ½–3 cups. Frozen berries may be used if kept frozen until mixed in.