- 1 ½ cup old fashioned rolled oats (gluten-free if necessary)
- 1 cup flour, such as all-purpose or oat (see note)
- ½ cup brown sugar, lightly packed
- ½ cup butter, melted*
- 1 teaspoon cinnamon
- ¼ teaspoon ground ginger, optional
- ⅛ teaspoon salt
Filling:
- 3 cups blueberries, fresh or frozen
- 2 teaspoons cornstarch
- 2 tablespoons lemon juice
- 2 tablespoons pure maple syrup
- 1 tablespoon chia seeds (see note)
- Make crumble. Preheat oven to 350F. Prepare crumble mixture by adding rolled oats, oat flour, brown sugar, salt, cinnamon and ginger to a mixing bowl. Melt butter and stir into dry ingredients until well combined.
- 1st Bake: Spread ⅔ of the crumble mixture into a parchment lined 8×8″ baking dish. Use the back of a spoon or the bottom of a measuring cup to firmly press the crumble into the dish. Bake the bottom layer of crumble in the oven at 350F for 12 minutes.
- Make blueberry filling. Add blueberries, lemon juice, and maple syrup to a small saucepan. While stirring often, bring the blueberry filling to a low boil over medium heat. The blueberries will become juicy.
- Stir in cornstarch and chia seeds to the juicy blueberries. Let filling simmer for about 10 more minutes. This helps thicken the blueberry sauce to create a spreadable blueberry jam to layer in our crumble bars. If the filling is too thin, add another teaspoon of cornstarch or chia seeds.
- Assemble! Once the bottom layer of crumble is baked and your filling is ready, spread all the homemade blueberry jam and then sprinkle the remaining ⅓ of the crumble mixture on top!
- 2nd Bake: Bake the blueberry bars at 350F for 20-22 minutes. Let cool completely before slicing for neat and even bars. Store in the fridge for 5-7 days or on the countertop for 2-3 days.
