1 box yellow cake mix
1 stick butter
2 1/2 c. sliced apples
1 tsp. cinnamon
1/2 c. sugar
1 c. sour cream
1 egg

Cut butter into dry cake mix until crumbly. Put in baking dish and bake at 350 degrees for 10 minutes. Take out of oven. Place apples on top of cake. Sprinkle cinnamon and sugar over apples.

Combine sour cream and egg. Pour over apple and return to oven, about 25-30 minutes.