Easy Apple Crisp FIVE ingredients! 1-cup flour 1-cup brown sugar 1/2 cup butter 2-3 big tart apples Ground cinnamon Peel apples and cut them into the bite size pieces. Layer them in a buttered casserole dish; sprinkle with cinnamon. Combine flour, brown sugar and butter into a bowl; cut in butter and mix until you have little crumbles; pour crumbles over the apples. Bake at 375 degrees for 30-40 minutes or until golden brown. Let cool; Serve with vanilla ice cream on top.