Preheat the oven to 350 degrees F
Spread the undrained pineapple tidbits on the bottom of a 9x13 baking dish.
Dump the Cherry (Apple or Blueberry) pie filling on top and try to spread around evenly.
Spread the dry yellow cake mix on top and try to make it as level as possible.
Melt the butter a little and them place it on top. I recommend trying to spread around the best as you can.
Bake in the oven for 50-55min, until the top, is golden.