Prepare your favorite pastry recipe. Line a pie pan with 1/2 of pastry and place a thin layer of cereal over pastry--this helps prevent the bottom crust from getting soggy.
Combine sugar, flour, cornstarch, salt and cinnamon. Stir in berries. Dot with butter. Cover with top crust and seal edges. Spread milk on top with a pastry brush and sprinkle with sugar. Bake at 425 degrees for 15 minutes. Lower oven to 350 degrees and bake 30 minutes longer until golden brown.