Use 1 stick of butter to coat bottom and sides of 9x13 inch cake pan. Melt the rest of that stick of butter and another stick of butter. In bottom of pan, pour 2 cans of apple pie filling. Sprinkle on cinnamon. Pour on top of that 1 box of yellow cake mix. Pour on melted butter, trying to cover entire surface with melted butter. Bake in 350 degree oven for 30 minutes.