In a greased casserole dish, pour a can of apple pie filling and distribute evenly across bottom with a spoon.
Sprinkle the powdered cake mixture over the apple pie filling. Even it out. Be sure to get the edges.
Pour melted butter over powdered mixture. Try to distribute evenly. It will clump in some areas. This is normal.
Bake for 45 minutes. Remove from oven. Sprinkle with mini marshmallows.
Place back in oven and broil for 30-45 seconds. Be ready and waiting with an oven mitt as it goes very fast!
You can substitute with cherry pie filling and a vanilla cake mix for a whole new dessert! We updated this November 2019 and found that we liked it better using ⅔ of the cake mix box as it seemed to result in a more moist dessert. You can cut down on the marshmallows to a half of a bag. No flavor was lost and it cut down on a lot of calories (130 for each piece!) Freezing: If you can't eat it all within a couple of days, just add slices to a freezer-proof container and store it in your freezer for up to three months. It will thaw out easily and still have that same delicious flavor that you love.Reheating: The cool thing about marshmallows is that they reheat quite easily. They will poof up when they're reheating. Once they cool down, they will deflate. Make sure your kids watch it.