1 pkg. yellow cake mix
1/2 c. butter, softened
1 tsp. ground cinnamon
2 lg. thinly sliced cooking apples
1 c. sour cream
1 egg
1/4 c. brown sugar

Heat oven to 350 degrees. Mix dry cake mix, butter, brown sugar, and cinnamon until crumbly. Reserve 2/3 cup. Press remaining mixture in ungreased 13 x 9 inch pan. Arrange apples on mixture in pan. Beat sour cream and egg until blended. Spread on apples. Spread reserved mixture on top. Bake 25 to 30 minutes.