Use a 9"x13" pan. Spread the crushed pineapple on the bottom, then dot the cherry pie filling on that. sprinkle the box of yellow cake mix over that. Butter,I cut it into small pieces then dot it onto top of cake mix. Bake it at 350 for 40 minutes. Everyones ovens are different, I have to bake it a little longer than this says. Top should be golden brown and crunchy.