Recipe: Blueberry Crumb Bars

updated May 28, 2019
Blueberry Crumb Bars

A buttery oat- and nut-packed crust doubles as a crumb topping in these summery blueberry bars.


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(Image credit: Joe Lingeman)

Fruit pies are undeniably one of the stars of summer desserts. They’re also a dessert I save for weekend baking, when I’ve got more time to make pie crust and prep delicate summer fruits. But sometimes, smack dab in the middle of the week, I feel like baking something with fresh fruit. My one requirement? It can’t take take too long to make. Enter: simple blueberry crumb bars.

For Easy Pie Bars, the Crust Doubles as the Topping, Too

These bars are what would happen if Dutch apple pie topping and blueberry pie filling got together for a summer fling. They’re sweet, crunchy, and, best of all, easy to make. One of the things that makes them so simple is that the crust and topping are made from the same mixture (which tastes like a buttery cinnamon granola). Half of it gets pressed firmly into the pan for the base, and the remaining mixture is strewn over the blueberry filling to create a streusel-like topping.

Although the crust tastes like granola, it’s made like a traditional pie crust — you cut cold butter into a flour mixture made with oats, chopped almonds, brown sugar, and cinnamon. Since my hands are warm in the summer, I use a pastry cutter to work the butter into the flour mixture. If your hands are cool, you can rub the butter into the mixture using a snapping motion with your fingers.

Don’t Underestimate the Power of Cornstarch

After pressing the bottom crust into the pan, it’s time to make the filling. It’s a simple combination of blueberries, lemon zest and juice, and cornstarch, which is a key component to the success of this dessert. As the blueberries cook and release their juices, the cornstarch thickens the filling and keeps it from spilling out. One time I accidentally forgot to add the cornstarch, and the bars came out of the oven looking like blueberry soup.

How to Serve and Store Fresh Fruit Crumb Bars

When the bars come out of the oven, they’re delicate — all hot fruit and buttery crust. If cut too soon, they’ll fall apart; allow the bars to cool for at least an hour before slicing.

In the hot summer, I store the bars in the refrigerator. While they taste great cool, they taste even better slightly warmed in the microwave. I’ve even been known to crumble a warm bar over a small bowl of vanilla ice cream — a summer sundae, if you will. It’s a treat you must try for yourself before summer fades into fall.

(Image credit: Joe Lingeman)

Blueberry Crumb Bars

A buttery oat- and nut-packed crust doubles as a crumb topping in these summery blueberry bars.

Serves 16

Nutritional Info


For the crust and topping:

  • Cooking spray

  • 1 cup

    all-purpose flour

  • 3/4 cup

    old-fashioned rolled oats

  • 1/2 cup

    finely chopped almonds

  • 1/2 cup

    packed light brown sugar

  • 1 teaspoon

    ground cinnamon

  • 1/4 teaspoon

    kosher salt

  • 1/2 cup

    (1 stick) cold unsalted butter, cut into 8 pieces

For the filling:

  • 2 cups

    fresh blueberries, washed and dried

  • 1/4 cup

    granulated sugar

  • 1 tablespoon


  • Finely grated zest of 1 medium lemon

  • Juice of 1 lemon (about 2 tablespoons)


  1. Arrange a rack in the middle of the oven and heat to 350°F. Line an 8-inch square baking dish with aluminum foil, leaving overhang on all sides. Grease the foil lightly with cooking spray; set aside.

  2. Make the crust and topping: Place the flour, oats, almonds, brown sugar, cinnamon, and salt in a large bowl and stir to combine. Add the butter and, using a pastry cutter or your fingertips, incorporate until no large pieces of butter remain. The mixture should be crumbly and hold together when squeezed.

  3. Set aside 1 cup of the mixture. Transfer the remaining mixture to the prepared baking dish and press it firmly and evenly into the pan to form the crust.

  4. Make the filling: Place the blueberries in a medium bowl. Add the sugar, cornstarch, and lemon zest and lemon juice and toss gently to combine. Transfer the mixture to the baking dish and spread into an even layer over the crust. Sprinkle the reserved 1 cup crumb mixture over the blueberries.

  5. Bake until the filling is bubbling and the top is golden-brown, about 40 minutes. Let cool at least 2 hours before cutting into bars.

Recipe Notes

Frozen blueberries: You can use frozen blueberries instead of fresh, but do not thaw before using.

Storage: Leftovers can be stored in an airtight container at room temperature for up to 3 days.