Preheat the oven to 350F. Take out a deep 9 x 13 baking pan.
Start with the crisp. Mix together the dry ingredients together in a medium bowl.
Add the cubed butter and rub the butter into the mixture until the mixture looks like lumps of wet sand or large crumbs. Store the topping in the freezer until needed.
Wash and dry your blueberries. Add them to your pan and toss the remaining ingredients for the filling together.
Take out the topping and crumble it evenly over the blueberry mixture. Try to get as many large crumbs as you can.
Bake for bout 40 - 50 minutes, or until the mixture is nice and bubbly.
Allow to cool completely before serving.
Notes
Add chopped nuts to the topping for added crunch.
Place aluminum foil over the crisp is you find the topping is browning too fast.
If you don't have blueberries, you can replace them with frozen, or any of your favorite fresh or frozen berries.