Name: Lemon Blueberry Crumb Bars
Prep time: 15 min
Cook time: 45 min
Total time: 2 h
Cuisine: American
Ingredients: For the crumb base and topping:; 1 1/2 cups all-purpose flour; 1/2 cup granulated sugar; 1/4 cup brown sugar; 1/2 teaspoon baking powder; 1/4 teaspoon salt; 1/2 cup unsalted butter, cold and cubed; 1 large egg; 1 teaspoon vanilla extract; For the lemon blueberry filling:; 2 cups fresh or frozen blueberries; 1/3 cup granulated sugar; 2 teaspoons cornstarch (3 tsp if using frozen berries); 1 tablespoon lemon zest; 2 tablespoons lemon juice

Why You’ll Love This Recipe

These bars are a delightful mix of flavors and textures: the sweet-tart blueberry and lemon center contrasts beautifully with the soft yet crisp crumb layers. They’re easy to slice, easy to serve, and hold up well at room temperature or chilled. Whether you need a make-ahead dessert or something special for brunch, these bars fit the bill perfectly.

Ingredients

(Tip: You’ll find the full list of ingredients and measurements in the recipe card below.)

For the crumb base and topping:

All-purpose flour
Granulated sugar
Brown sugar
Baking powder
Salt
Unsalted butter (cold and cubed)
Egg
Vanilla extract

For the lemon blueberry filling:

Fresh or frozen blueberries
Granulated sugar
Cornstarch
Lemon zest
Lemon juice

Directions

Preheat oven: Set to 350°F (175°C). Grease or line an 8×8 or 9×9-inch baking pan with parchment paper.
Make the crumb mixture: In a large bowl, combine flour, sugar, brown sugar, baking powder, and salt. Cut in the cold butter using a pastry cutter or fork until the mixture resembles coarse crumbs. Mix in egg and vanilla until just combined.
Form the base: Press about two-thirds of the crumb mixture into the bottom of the prepared pan to form an even crust.
Prepare the filling: In a separate bowl, mix blueberries with sugar, cornstarch, lemon zest, and lemon juice until evenly coated.
Assemble the bars: Spoon the blueberry mixture evenly over the crust. Crumble the remaining dough on top.
Bake: Bake for 40–45 minutes, or until the top is lightly golden and the filling is bubbling.
Cool and slice: Let the bars cool completely in the pan before slicing into squares. For clean cuts, chill in the fridge for 1 hour before slicing.

Servings and timing

This recipe makes about 9–12 bars, depending on how you slice them.
Prep time: 15 minutes
Bake time: 45 minutes
Cooling time: 1 hour
Total time: 2 hours

Variations

Glazed topping: Drizzle with a lemon glaze made from powdered sugar and lemon juice for extra zing.
Add nuts: Sprinkle chopped almonds or pecans into the crumb topping for crunch.
Mixed berries: Swap some of the blueberries for raspberries or blackberries.
Vegan version: Use a plant-based butter and a flax egg to make it vegan-friendly.
Gluten-free: Substitute the all-purpose flour with a 1:1 gluten-free baking flour.

Storage/Reheating

Store bars in an airtight container at room temperature for up to 2 days or refrigerate for up to 5 days.
To freeze, layer bars between parchment paper in a freezer-safe container and freeze for up to 2 months. Thaw in the refrigerator before serving.
These bars are best served chilled or at room temperature. No reheating is necessary.

FAQs

Can I use frozen blueberries?

Yes, just use them straight from the freezer. Add an extra teaspoon of cornstarch to help absorb the additional moisture.

Can I make these bars ahead of time?

Absolutely. They’re perfect for making a day in advance and actually taste better after resting.

How do I keep the bottom crust from getting soggy?

Make sure to press the crust firmly into the pan and bake until golden to prevent sogginess.

Can I double the recipe?

Yes, double the ingredients and bake in a 9×13-inch pan. Add 5–10 minutes to the baking time.

What type of lemon is best?

Fresh lemons are best for both juice and zest. Avoid bottled lemon juice for optimal flavor.

Can I use bottled lemon juice?

Fresh lemon juice is recommended for its bright flavor, but bottled can be used in a pinch.

Why is my crumb topping not crisp?

If the butter was too warm or the topping wasn’t baked long enough, it may turn out soft. Use cold butter and bake until golden.

Can I make these bars with other fruits?

Yes, peaches, raspberries, or a mix of berries work beautifully with the same filling base.

Should I refrigerate the bars?

Yes, especially if you live in a warm climate or want them to last longer. They firm up nicely when chilled.

Can I serve these warm?

You can, but they hold their shape best when cooled. Serve slightly warm with ice cream for a dessert-style treat.

Conclusion

Lemon Blueberry Crumb Bars are everything you want in a fruity dessert: buttery, tart, sweet, and crumbly. With just the right balance of bright citrus and juicy berries, they’re the kind of treat you’ll want to make again and again. Easy to transport, easy to slice, and absolutely delicious, these bars are a must-try for any season.