Blueberry Crumb Bars are the perfect blend of sweet, tangy, and buttery goodness in every bite. With a luscious blueberry filling nestled between a tender crust and a golden crumb topping, these bars offer a delightful contrast of textures. The juicy berries burst with flavor, while the crumbly topping adds a satisfying crunch. Ready in just 30 minutes of prep, they’re an easy yet impressive treat for any occasion.
After baking for an hour and cooling for two, these bars transform into a dessert that’s both comforting and indulgent. Each square is packed with fresh, vibrant blueberries, offering a hint of tartness balanced by the sweetness of the crumb. Light on calories but rich in flavor, they’re perfect for sharing or savoring solo. Whether for a picnic, potluck, or afternoon snack, these bars are sure to become a favorite.
Ingredients for Blueberry Crumb Bars
- Blueberry Filling:
- 5 cups (840 g) blueberries, divided
- ½ cup (100 g) sugar
- 2 Tablespoons cornstarch
- ⅛ teaspoon salt
- 1 Tablespoon lemon juice (freshly squeezed for best flavor)
- ½ teaspoon vanilla extract
- 1 Tablespoon butter (unsalted)
- Crumb Base/Topping:
- 3 ¼ cups (405 g) all-purpose flour
- ¾ cup (150 g) sugar
- ¼ cup (50 g) light brown sugar, tightly packed
- ½ teaspoon baking powder
- 1 teaspoon cornstarch
- ½ teaspoon salt
- 1 cup (227 g) cold unsalted butter, cut into small cubes
- 1 large egg yolk
- ½ teaspoon vanilla extract
Step-by-Step Instructions
- Preheat oven to 350°F (175°C) and lightly grease a 9×13-inch glass baking dish. Set aside.
- Prepare the blueberry filling: In a small saucepan, combine 3 cups (505 g) of blueberries, sugar, cornstarch, salt, and lemon juice. Cook over medium-low heat, stirring frequently, until the blueberries release their juices and the mixture becomes very liquidy (about 5-8 minutes).
- Increase the heat to medium-high and bring the mixture to a boil, stirring constantly. Boil for 1 minute, then remove from heat.
- Add the remaining 2 cups of blueberries, butter, and vanilla extract. Stir until the butter is melted. Set aside to cool while preparing the crust.
- Make the crumb base/topping: In a food processor, combine flour, sugars, baking powder, cornstarch, and salt. Pulse briefly until mixed.
- Sprinkle the cold butter pieces evenly over the dry ingredients. Pulse until the mixture resembles coarse crumbs.
- Add the egg yolk and vanilla extract. Pulse again until the mixture just begins to cling together.
- Assemble the bars: Press half of the crumb mixture evenly into the bottom of the prepared baking dish to form a crust.
- Spread the cooled blueberry filling evenly over the crust.
- Sprinkle the remaining crumb mixture evenly over the filling.
- Bake: Transfer to the oven and bake for 55-60 minutes, or until the top is golden brown.
- Cool: Allow the bars to cool completely (2-3 hours) before slicing. For warm bars, use a spoon as they will fall apart if sliced too soon.
Perfect Pairings: Serving Suggestions
These Blueberry Crumb Bars are delicious on their own, but they shine even brighter with a scoop of vanilla ice cream or a dollop of whipped cream. For a refreshing twist, serve with a side of fresh berries or a drizzle of honey. They’re also perfect with a cup of coffee or tea for a cozy afternoon treat!
Keep It Fresh: Storage and Reheating Tips
Store your bars in an airtight container at room temperature for up to 2 days or in the fridge for up to 5 days. To reheat, pop them in the microwave for 10-15 seconds or warm them in a 300°F (150°C) oven for 5-10 minutes. For longer storage, freeze individual slices wrapped in plastic wrap and thaw at room temperature when ready to enjoy.
Mix It Up: Recipe Variations
Feel free to get creative with this recipe! Swap blueberries for raspberries, blackberries, or a mix of your favorite fruits. For a nutty twist, add ½ cup of chopped almonds or pecans to the crumb topping. If you’re feeling indulgent, sprinkle a handful of white chocolate chips over the filling before adding the top layer.
Time-Saving Hacks
Short on time? Use pre-washed blueberries to skip the rinsing step. You can also prepare the blueberry filling a day ahead and store it in the fridge. For the crust, pulse the dry ingredients and butter in the food processor the night before, then add the egg yolk and vanilla just before baking.
Essential Equipment Guidance
A 9×13 glass baking dish is ideal for even baking, and a food processor makes quick work of the crumb mixture. If you don’t have a food processor, use a pastry cutter or your fingers to blend the butter into the dry ingredients. A silicone spatula is handy for stirring the blueberry filling without scratching your saucepan.
Blueberry Crumb Bars
Ingredients
Blueberry Filling
- 5 cups blueberries divided
- ½ cup sugar
- 2 Tablespoons cornstarch
- ⅛ teaspoon salt
- 1 Tablespoon lemon juice
- ½ teaspoon vanilla extract
- 1 Tablespoon butter
Crumb Base/Topping
- 3 ¼ cups all-purpose flour
- ¾ cup sugar
- ¼ cup light brown sugar tightly packed
- ½ teaspoon baking powder
- 1 teaspoon cornstarch
- ½ teaspoon salt
- 1 cup cold unsalted butter cut into small cubes
- 1 large egg yolk
- ½ teaspoon vanilla extract
Instructions
- Preheat oven to 350F (175C) and lightly grease a 9×13 glass baking dish. Set aside.
- In small saucepan, combine 3 cups blueberries (505g), sugar, cornstarch, salt, and lemon juice over medium-low heat.
- Stir frequently until the blueberries release their juices, and the mixture is very liquidy (about 5-8 mins).
- Increase heat to medium-high and bring to a boil, stirring constantly.
- Boil (still stirring constantly) for 1 minutes and remove from heat.
- Add remaining 2 cups of blueberries, butter, and vanilla extract and stir until butter is melted.
- Allow to cool while you prepare your crust.
- To prepare your cookie crust, combine flour, sugars, baking powder, cornstarch, and salt in a food processor and pulse briefly until combined.
- Sprinkle your butter pieces evenly over the dry ingredients and pulse until the mixture resembles coarse crumbs.
- Add egg and vanilla extract and pulse again until mixture just begins to cling together.
- Pour ½ of your cookie batter into the bottom of your prepared pan and use your hands or the back of a spoon to press evenly into the bottom of the pan to form a crust.
- Pour your cooled blueberry filling evenly over the crust.
- Use your hands to sprinkle the remaining crust mixture evenly over the top of the filling.
- Transfer to the oven and bake on 350F (175C) for 55-60 minutes or until the top of the blueberry crumb bars is golden brown.
- Allow to cool completely (2-3 hours) before slicing and serving. If you prefer to enjoy these warm the crumb bars WILL fall apart if sliced before they have cooled and set, so plan to use a spoon!