Enjoy all of Summer's bounty of berries with my Mixed Berry Crumble Bars that are so easy to make and bursting with bright tart and sweet berry flavor! These bars are simple because you make one mixture to form the base crust and the crumble topping. There's a lightly sweetened blend of raspberries, blueberries and blackberries that forms the filling and it's so juicy and full of Summer vibes. If you love this idea, then try my Blueberry Pie Bars too!
WHY YOU WILL LOVE THIS RECIPE:
- Easy to make - this recipe is easy to prepare because you only need to make one mixture that you can use to make the crust and the topping.
- Juicy triple berry filling - the filling is made of raspberries, blackberries and blueberries with a bright tart and sweet flavor.
- Buttery oat crumble - the crumble has just the right amount of oats for some texture and almond flour which adds extra richness and a sweet floral note that complements the fruit.
- One pan recipe - you don't need to pre-cook the filling for this recipe. Instead you just blend the berries with sugar and spread them over the pre-baked crust.
- All-purpose flour - simple all-purpose flour works great in this recipe. I use unbleached flour.
- Butter - you can use salted butter to make the crust for a rich dairy taste. You can also use unsalted butter and then add a pinch of salt with it.
- Pure vanilla extract - vanilla will elevate and enhance the white chocolate. I like this Madagascar Bourbon Vanilla extract.
- Brown sugar - you can use dark brown or light brown sugar. It adds a nice butterscotch taste. Make sure you pack it down in your measuring cup if you are not using a scale to weigh ingredients.
- Granulated sugar - white granulated sugar adds the right amount of sweetness so that the molasses from the brown sugar doesn't overpower the taste of the blueberries.
- Almond flour - you can also use ground almonds. This adds extra richness and a floral note that really makes the crust taste special!
- Oats - you'll need quick oats for this recipe. Quick oats are broken down more so they cook faster and bake into the crust a bit better than rolled oats.
- Blueberries - you can use fresh or frozen blueberries to make the filling since it gets cooked down anyway.
- Blackberries - you can use fresh or frozen blackberries for this recipe
- Raspberries - you can use fresh or frozen raspberries for this recipe. If you use frozen, then my advice is to pick out the nice whole ones as crumbled raspberries will make the filling more mushy.
- Cherry or strawberry preserves - a bit of preserves or jam bumps up the berry flavor and contributes some of the sweetness to these bars.
STEP BY STEP INSTRUCTIONS
- STEP 1). Make the base and topping. Combine flour, oats, almond flour brown sugar, baking powder and salt together in a large bowl. Make sure that it is evenly blended with no lumps of brown sugar. Add the cooled melted butter and stir until the mixture is evenly combined and it holds together in moist clumps with no dry spots remaining.
- STEP 2). Reserve the topping. Remove one-third of the crumb/crust mixture and set it aside for the topping.
- STEP 3). Form the base crust. Tip ⅔ of the mixture into the prepared baking pan. Press it evenly into the pan with your hands, and then smooth it out with the bottom of a measuring cup. Bake until golden and then set aside to cool slightly.
- STEP 4). Make the filling. Place the berries in a medium bowl. Add sugar, flour and cornstarch and toss together to blend evenly to coat the berries. Add the preserves and mix it in gently.
- STEP 5). Top the bars. Spoon the filling over the crust and spread it out evenly. Crumble the remaining crust mixture over the filling leaving it in clumps.
- STEP 6). Bake for about 30–35 minutes until the top is golden brown and the berry filling is bubbling around the edges.
- STEP 7). Cool. Transfer pan to a wire rack and let the bars cool completely in the pan. Then, cover and refrigerate the cooled bars for 2 hours.
EXPERT BAKING TIPS FOR BERRY CRUMBLE BARS
- Cool the butter. Having the melted butter cooled to lukewarm or room temperature will ensure that your crust/crumble isn't greasy.
- Don't over-cook the filling. The filling is ready as soon as it starts to bubble and thickens. If you let it boil too long, then the corn starch can actually break down and it will lose its ability to hold in the water.
- Let the bars cool completely then chill. These bars will hold together best once they are completely chilled.
- Let the base crust cool slightly before spreading the filling on top. This will help prevent a soggy bottom.
Yes, you can, but I always prefer butter for its superior flavor. Butter also contains trace amounts of milk proteins which will brown in the oven, so if you use shortening then the bars will be more pale and less golden.
These Mixed Berry Crumble Bars are finished baking when the crumble on top is golden and the juices from the berry filling is bubbling around the sides.
I do not recommend freezing these bars as they tend to become soggy once thawed due to the high moisture of the filling.
You can make this recipe with other berries, such as mulberries in place of blackberries, however I do not recommend using strawberries as they contain a high amount of moisture which will affect the texture of the bars.
You can use either! I have tested this recipe with both fresh and frozen berries. With frozen berries you will need to increase the baking time. I also suggest letting them thaw for just 10-15 minutes in a strainer to let any excess ice crystals melt away. Do not thaw them completely though - they should still be frozen inside.
If you love baking with berries, check out these recipes!Lemon Blueberry Crumb CakeEasy Blueberry Pie BarsStrawberry Crumb CakeBrown Butter Peach Crumb CakeLemon Blueberry Streusel MuffinsBlueberry Pie BarsWhite Chocolate Raspberry BlondiesEasy Lemon Tart RecipeLemon Raspberry CakeStrawberry Matcha Latte Cheesecake BarsStrawberry Lemon CakeAlmond Raspberry Lemon Bars
Looking for more easy bar recipes? Try these:
Baking with berries
These are my favorite recipes to make with berries:
Mixed Berry Crumble Bars
Crust and topping:
- 1 cup plus 2 tbsp 160g all purpose flour
- ⅔ cups 60g quick oats
- ¼ cup 25g almond flour
- ½ cup 110g packed light brown sugar
- ½ teaspoon baking powder
- ¼ teaspoon salt
- ½ cup unsalted butter melted and cooled
Triple Berry Filling:
- 1 cup 120g frozen blackberries
- 1 cup 120g frozen raspberries
- 1 cup 120g frozen blueberries
- 3 tablespoon 40g granulated sugar
- 1 tablespoon 9g all-purpose flour
- 1 tablespoon 8g corn starch
- 2 tablespoon 30ml cherry or strawberry preserves
- Preheat oven to 350°F. Line an 8-inch square baking pan with parchment paper, leaving an overhang on the sides to easily lift the bars out of the pan.
- Make the base and topping. Combine flour, oats, almond flour, brown sugar, baking powder, and salt together in a large bowl. Make sure that it is evenly blended with no lumps of brown sugar. Add the cooled melted butter and stir until the mixture is evenly combined and it holds together in moist clumps with no dry spots remaining. Remove one-third of the mixture and set it aside for the topping.
- Tip two-thirds of the mixture into the prepared baking pan. Press it evenly into the pan with your hands, and then smooth it out with the bottom of a measuring cup. Bake for 12 minutes, and then remove from the oven to cool slightly.
- Make the filling. Place the berries in a medium bowl. Combine sugar, flour and cornstarch in a smaller bowl and mix to blend evenly. Add the flour mixture to the berries and toss together to coat the berries. Add the preserves and mix it in gently. Spoon the filling over the crust and spread it out evenly. Crumble the remaining crust mixture over the filling leaving it in clumps. Bake for about 30–35 minutes until the top is golden brown and the berry filling is bubbling around the edges.
- Transfer pan to a wire rack and let the bars cool completely in the pan. Then, cover and refrigerate the cooled bars for 2 hours.