Blueberry Oat Crumble Bars

Looking for a super-easy, healthy, crowd-pleasing snack or dessert? Try these blueberry oat crumble bars! These crumble bars aren’t overly sweet and the blueberry flavor is so good, it makes them perfect for breakfast, brunch, snacks, or even a healthy dessert.  These bars will keep airtight at room temperature for up to 1 week, in the fridge for up to 10 days, or in the freezer for up to 6 months.

Blueberry Oat Crumble Bar
Blueberry Oat Crumble Bar

Also, instead of blueberries, you can use any other fruit you’d like. I’ve made them with blackberries, but strawberries, peaches, cherries, cranberries or anything else you’re thinking about in the fruit category would work just fine. To the right is a picture of what mine looked like.

Because of the great healthiness (and of course the great taste), we are using them for this recipe today. If you don’t already know about the health benefits of eating blueberries everyday, here’s a quick overview:  Studies show that eating blueberries everyday helps fend off heart disease, cancer, brain aging, and even more. 

According to a study published in Circulation: Journal of the American Heart Association eating at least three servings of blueberries and strawberries every week can save women from heart attacks. They can also lower your blood pressure, help to protect your lungs and also improve insulin sensitivity. While we could go on and on about the extraordinary health benefits of blueberries, we will just leave it at this: EAT THE BLUEBERRIES…

Blueberry Oat Crumble Bar Recipe


Crust and Crumble Topping

  • 1/2 cup (1 stick) unsalted butter, melted
  • 1 cup all-purpose flour
  • 3/4 cup old-fashioned whole-rolled oats (don’t use quick cook or instant)
  • 1/2 cup granulated sugar
  • 1/4 cup light brown sugar, packed
  • pinch salt, optional and to taste

Blueberry Layer

  • 12 ounces (2 cups) blueberries or other fruit (fresh or frozen; if using frozen you do not need to be thaw)
  • 1/3 cup granulated sugar
  • 2 tablespoons lemon juice
  • 2 teaspoons cornstarch


  1. Preheat oven to 350F.
  2. Line an 8-inch square pan with aluminum foil and spray with cooking spray; set aside.
    1. Lining the pan helps with cleanup and is recommended.

Crust and Crumble Topping

  • In a large, microwave-safe bowl melt the butter, about 1 minute on high power.
  • Add the flour, oats, sugars, optional salt, and stir to combine. Mixture will be dry and sandy with some larger, well-formed crumble pieces.
  • Set 1 heaping cup mixture aside to be sprinkled on later as crumble topping.
  • Transfer remaining mixture to prepared pan, and using a spatula or your fingers, hard-pack the mixture to create an even, smooth, flat crust; set aside.

Blueberry Layer

  1. In a large mixing bowl, add all ingredients and toss to combine.
    • If sugar hasn’t dissolved fully that’s okay, because it liquifies while baking.
  2. Evenly distribute blueberry mixture over the crust.
  3. Evenly sprinkle with the reserved heaping 1 cup crumble topping mixture.
  4. Bake for about 55 minutes, or until edges are set and center has just set. The crumble topping should appear set and very pale golden.
    • If using fresh berries, baking time will be reduced by around 10-15 minutes, possibly less.
    • Bars may take longer than 55 minutes if blueberries are very juicy.
    • Watch your bars, not the clock, when evaluating doneness.
  5. Place pan on a wire rack and allow bars to cool for at least 30 minutes before slicing and serving.
    • If you try to slice bars before they’ve cooled completely, they’ll be extremely messy and could fall apart.

Thanks to Averie Cooks for this great and healthy recipe.

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