Stir together flour, brown sugar, granulated sugar, salt and cinnamon. Cut butter pieces in until crumbly and no lumps of butter remain. Sprinkle evenly on top (about 2 heaping teaspoonfuls per cup. Lightly press into batter. Bake at 325° for 25 minutes or until toothpick comes out clean. Cool.
May also add 2 cups of fresh blueberries. (bake at 350° for 25-28 minutes.