Preheat the oven to 375F
Spray a 9" square baking pan with nonstick spray, set aside.
Take a large bowl combine all the Crumb ingredients with fork until they are combined well. Set aside.
In another large bowl mix together all the cake ingredients except the blueberries until well incorporated then fold in the blueberries.
Spread the cake batter into the prepared pan and sprinkle evenly with the crumb topping.
Bake for 45 minutes until a toothpick inserted in the center comes out clean.
Allow the cake to cool for 10 minutes before attempting to remove