Blueberry Crumb Bars Recipe photo by Taste of Home

Blueberry Crumble Bars

Total Time
Prep: 20 min. Bake: 20 min. + cooling
Fast and flavorful, blueberry crumble bars combine sweet blueberries with a delightfully tasty oat topping and crust that comes together in a flash.

Updated: Jun. 14, 2024

Blueberry crumble bars are the perfect anytime treat. Try one as a delicious after-dinner dessert, as a breakfast pastry with your morning coffee or as the life-giving afternoon snack that inspires you to finish your workday. There are many recipes to make with fresh blueberries, and cobblers, crumbles, crisps and buckles are some of the easiest and most popular. The summer berries in this crumble pair perfectly with the sweet richness of the buttery oat topping and crust.

Shortcuts like using blueberry preserves and a yellow cake mix save time and effort without compromising flavor. The preserves mixed with fresh berries offer a rich, fruity filling, while the yellow cake mix streamlines the baking process. These shortcuts make it possible to whip up a batch of these delightful bars super fast, moving them to the top of our favorite quick and easy desserts list, especially when we have a busy schedule or need a last-minute dish.

Ingredients for Blueberry Crumble Bars

  • Yellow cake mix: Baking with the best yellow cake mix saves you the headache of gathering the ingredients and requires only a few minutes of prep.
  • Old-fashioned oats: A touch of sweetness sets this grain apart. Old-fashioned oats and quick-cooking oats are interchangeable, although the quick-cooking oats are more processed and may slightly change the dessert’s texture.
  • Blueberry preserves: Blueberry preserves add flavor and help thicken the fruit filling without extra cornstarch or flour. Use preserves instead of jams and jellies, which don’t contain whole fruit. Any brand will do, but we like Bonne Maman Wild Blueberry the most (Bonne Maman is one of our favorite strawberry jam brands too!).
  • Butter: Butter adds flavor and fat to this blueberry crumble bars recipe. Salted or unsalted butter is fine; adjust any additional salt accordingly.
  • Fresh blueberries: Summer is the blueberry’s time to shine! I love making blueberry crumble bars with the last few berries left in the basket after a few days of snacking on them, just before they go bad. Blueberries last only a few days on the counter and up to two weeks in the fridge, but they are best that first week. Want a taste of sunshine in the cold winter months? Learn how to freeze blueberries and then defrost them for crumble bars anytime.
  • Lemon juice: Freshly squeezed lemons give the bars a fuller flavor profile and add a touch of tartness. Juicing lemons is easy, but bottled lemon juice can work in a pinch.
  • Cinnamon and pecans: The zippy flash of spice and the earthy flavors from the nuts add a fabulous finish to the topping of our dessert.

Directions

Step 1: Build the crust

Preheat the oven to 350°F. In a large bowl, combine the cake mix, oats and butter until crumbly. Press 3 cups into a greased 9-inch square baking pan. Bake for 15 minutes, remove from the oven and cool on a wire rack for five minutes.

Step 2: Mix the filling and assemble the crumble

Meanwhile, combine the preserves, blueberries and lemon juice in a small bowl. Spread over the crust. Stir the pecans and cinnamon into the remaining crumb mixture. Sprinkle the mixture over the top of the filling.

Step 3: Bake the crumble

Bake the crumble until the top is lightly browned, 18 to 20 minutes. Cool on a wire rack before cutting into bars.

Editor’s Tip: These are fantastic served warm with a scoop of ice cream, but I like to cool them completely in the refrigerator so they cut into more perfect squares.

Blueberry Crumble Bar Variations

  • Try other fruit options: Whatever preserves your grocer has on the shelf can inspire what type of crumble bars you can make, as long as you can pair the preserves with fresh (or frozen) fruit. Cherries come to my mind first, and I love a more tart version with cranberries (try orange juice instead of lemon for this one). Because I hail from Montana, huckleberries are always an option. Or, mix and match multiple berries! Our popular raspberry crumble bars take longer but are always a crowd-pleaser.
  • Zest it up: Adding a little grated lemon zest (the outer skin of the peel) to your blueberry mixture can provide more contrasting tartness to the berries’ sweetness. Anytime I see lemon juice in a recipe, I wonder if some lemon zest would also be good. The answer is usually yes.

How to Store Blueberry Crumble Bars

Store blueberry crumble bars in an airtight container for up to two days at room temperature and five days in the refrigerator.

Can you freeze blueberry crumble bars?

If you want to freeze this dessert, wrap individual bars tightly and store them in a freezer-safe bag or container for up to three months. To defrost the bars, put them in the refrigerator overnight and serve cold, or reheat them in the oven for about 10 minutes at 350° to serve warm.

Blueberry Crumble Bar Tips

Can you use frozen blueberries for crumble bars?

Yep, you can use frozen blueberries. Thaw and drain them well before adding them to the filling mixture to avoid excess moisture, which can make the bars soggy.

What else can you serve with blueberry crumble bars?

Like many of our other favorite fruity summer desserts, warm blueberry crumble bars scream for a scoop of vanilla ice cream or homemade whipped cream. You can get creative with your ice cream flavors, butter pecan ice cream and blueberry ice cream are good choices, or spike the whipped cream with a touch of bourbon or rum.

Blueberry Crumble Bars

Prep Time 20 min
Cook Time 20 min
Yield 1 dozen.

Ingredients

  • 1 package yellow cake mix (regular size)
  • 2-1/2 cups old-fashioned oats
  • 3/4 cup butter, melted
  • 1 jar (12 ounces) blueberry preserves
  • 1/3 cup fresh blueberries
  • 1 tablespoon lemon juice
  • 1/3 cup finely chopped pecans
  • 1 teaspoon ground cinnamon

Directions

  1. Preheat oven to 350°. In a large bowl, combine cake mix, oats and butter until crumbly. Press 3 cups into a greased 9-in. square baking pan. Bake 15 minutes. Cool on a wire rack 5 minutes.
  2. Meanwhile, in a small bowl, combine preserves, blueberries and lemon juice. Spread over crust. Stir pecans and cinnamon into remaining crumb mixture. Sprinkle over top.
  3. Bake until lightly browned, 18-20 minutes. Cool on a wire rack before cutting into bars.

Nutrition Facts

1 bar: 429 calories, 18g fat (9g saturated fat), 30mg cholesterol, 362mg sodium, 66g carbohydrate (38g sugars, 2g fiber), 4g protein.

Think of this as a blueberry crisp turned into a hand-held treat. Oats and fresh blueberries combine for a sweet, uncomplicated dish. —Blair Lonergan, Rochelle, Virginia