Once you try this recipe you will never want another! Perfection in every bite!
Preheat oven to 375°F. Prepare a 9x13 pan with baking spray or coating with butter.
Place blueberries in a bowl. Add brown sugar, flour, and cinnamon. Stir gently and make sure every blueberry is covered in the sugar mixture. Set aside.
Combine the oats, flour, brown sugar, baking powder, baking soda, and cinnamon together. Add in the cubed butter and use your hands to combine. You want the butter to be pea-sized and coated entirely. You should have 6 cups.
Spread 3 cups over the bottom of your prepared pan and press flat. Pour the blueberry mixture over top and press down with rubber spatula. Pour remaining crisp mixture over top of the blueberries and bake uncovered at 375°F for 35-45 minutes.
Be sure to read the blog post if you are using frozen blueberries! Your baking time will change.