1 pkg. yellow cake mix with pudding
1/2 c. butter
1/4 c. brown sugar
1/2 tsp. cinnamon
2 apples, thinly sliced (or more)
1 c. sour cream
1 egg

Combine cake mix and butter until crumbly. Reserve 2/3 cup for top and add sugar and cinnamon; mix well and set aside. Press remaining onto bottom of ungreased 9x13 inch pan. Arrange apple slices over base.

Blend sour cream and egg; spread over apples. Sprinkle topping mixture. Bake at 350 degrees for 25-30 minutes. Serve warm. Makes 12-15 squares. Refrigerate leftovers.