These Blueberry Crumble Bars are the perfect combination of a buttery oat crust, sweet-tart blueberry filling, and a golden crumb topping. Made with simple pantry ingredients and juicy blueberries, these easy dessert bars are ideal for summer gatherings, afternoon snacks, or a delicious make-ahead treat. Every bite is packed with fruity flavor and a satisfying crumble texture that’s hard to resist.
Why You’ll Love This Recipe
- Easy to make with everyday ingredients
- Buttery oat crust and crisp crumble topping
- Bursting with juicy blueberry flavor
- Perfect for picnics, bake sales, and holidays
- Great for making ahead of time
- Freezer-friendly for easy storage
- Delicious served warm or chilled
Ingredients
Crust & Crumble
- 1½ cups all-purpose flour
- 1½ cups quick-cooking oats
- 1½ cups granulated sugar, divided
- ½ teaspoon ground cinnamon
- ½ teaspoon baking soda
- ¾ cup cold butter, cubed
Blueberry Filling
- 2 cups fresh or frozen blueberries
- 2 tablespoons cornstarch
- 2 tablespoons fresh lemon juice
Instructions
- Preheat your oven to 375°F (190°C). Lightly grease a 9×13-inch baking dish or line it with parchment paper for easy removal.
- In a large mixing bowl, combine the flour, oats, 1 cup of the sugar, cinnamon, and baking soda.
- Add the cold cubed butter and cut it into the dry ingredients using a pastry cutter or two forks until the mixture resembles coarse crumbs.
- Reserve about 2 cups of the crumb mixture for the topping.
- Firmly press the remaining crumb mixture into the bottom of the prepared baking dish to create an even crust.
- In a medium saucepan, combine the blueberries, remaining ½ cup sugar, cornstarch, and lemon juice.
- Cook over medium heat, stirring constantly, until the mixture comes to a gentle boil and thickens, about 2–3 minutes.
- Spread the warm blueberry filling evenly over the prepared crust.
- Sprinkle the reserved crumble mixture evenly over the blueberry layer.
- Bake for 25–30 minutes, or until the topping is lightly golden brown and the filling is bubbling around the edges.
- Allow the Blueberry Crumble Bars to cool completely before slicing into squares.
- Cut into 24 bars and serve.
Tips & Tricks
- Fresh blueberries provide the best texture, but frozen blueberries work just as well without thawing.
- Chill the bars before slicing for cleaner edges.
- Use old-fashioned oats for a slightly chewier crumble.
- Add a pinch of nutmeg for extra warmth and flavor.
- Line the baking pan with parchment paper to make lifting and slicing easier.
- Serve warm with vanilla ice cream for an extra-special dessert.
Details
Prep Time: 15 minutes
Cook Time: 30 minutes
Cooling Time: 1 hour
Total Time: 1 hour 45 minutes
Yield: 24 bars
Category: Dessert
Method: Baking
Cuisine: American
Difficulty: Easy
Dietary Notes: Vegetarian
Notes
- Frozen blueberries can be used directly from the freezer.
- Add lemon zest for a brighter citrus flavor.
- These bars taste even better the next day after the filling has fully set.
- Sprinkle powdered sugar over the cooled bars before serving for an elegant finish.
Nutrition (Approximate Per Bar)
- Calories: 185
- Protein: 2g
- Carbohydrates: 30g
- Fat: 7g
- Saturated Fat: 4g
- Fiber: 2g
- Sugar: 18g
- Sodium: 75mg
FAQ
Can I use frozen blueberries?
Yes. Frozen blueberries work perfectly and do not need to be thawed before cooking.
How do I keep the crumble topping crisp?
Use cold butter and avoid overmixing the crumble mixture. Bake until the topping is lightly golden.
Can I make Blueberry Crumble Bars ahead of time?
Absolutely. These bars actually taste better after they’ve cooled completely and can be made a day in advance.
Can I substitute other berries?
Yes. Raspberries, blackberries, strawberries, or mixed berries all work well in this recipe.
Why are my bars falling apart?
Be sure to allow the bars to cool completely before cutting so the filling has time to set.
Can I reduce the sugar?
Yes. You can reduce the sugar slightly if your blueberries are naturally sweet without affecting the texture.
Storage
Room Temperature: Store in an airtight container for up to 2 days.
Refrigerator: Keep refrigerated for up to 5 days.
Freezer: Freeze individual bars in airtight containers or freezer bags for up to 3 months.
Reheating: Enjoy chilled, at room temperature, or warm individual bars in the microwave for 15–20 seconds.
Similar Recipes
Blueberry Crumble Bars
Ingredients
Crust & Crumble
- 1½ cups all-purpose flour
- 1½ cups quick-cooking oats
- 1½ cups granulated sugar divided
- ½ teaspoon ground cinnamon
- ½ teaspoon baking soda
- ¾ cup cold butter cubed
Blueberry Filling
- 2 cups fresh or frozen blueberries
- 2 tablespoons cornstarch
- 2 tablespoons fresh lemon juice
Instructions
- Preheat your oven to 375°F (190°C). Lightly grease a 9×13-inch baking dish or line it with parchment paper for easy removal.
- In a large mixing bowl, combine the flour, oats, 1 cup of the sugar, cinnamon, and baking soda.
- Add the cold cubed butter and cut it into the dry ingredients using a pastry cutter or two forks until the mixture resembles coarse crumbs.
- Reserve about 2 cups of the crumb mixture for the topping.
- Firmly press the remaining crumb mixture into the bottom of the prepared baking dish to create an even crust.
- In a medium saucepan, combine the blueberries, remaining ½ cup sugar, cornstarch, and lemon juice.
- Cook over medium heat, stirring constantly, until the mixture comes to a gentle boil and thickens, about 2–3 minutes.
- Spread the warm blueberry filling evenly over the prepared crust.
- Sprinkle the reserved crumble mixture evenly over the blueberry layer.
- Bake for 25–30 minutes, or until the topping is lightly golden brown and the filling is bubbling around the edges.
- Allow the Blueberry Crumble Bars to cool completely before slicing into squares.
- Cut into 24 bars and serve.
Notes
- Frozen blueberries can be used directly from the freezer.
- Add lemon zest for a brighter citrus flavor.
- These bars taste even better the next day after the filling has fully set.
- Sprinkle powdered sugar over the cooled bars before serving for an elegant finish.
Conclusion
These Blueberry Crumble Bars are the perfect homemade dessert for any occasion. With their buttery oat crust, sweet blueberry filling, and crisp golden crumble topping, they’re easy to prepare and always a crowd-pleaser. Whether you’re serving them at a picnic, holiday gathering, or enjoying one with your afternoon coffee, this easy blueberry dessert is sure to become a favorite.