Pre-heat the oven to 350. Then get out two 9 inch cake pans and pour half of the melted butter into each of them. Brush some of the butter along the sides of the pans as well to grease them thoroughly. Lay 5 pineapple slices in each of the prepared pans with 1 in the center and the other 4 around it. Place a cherry in the center of each of the pineapple slices. Then pack 1/2 a cup of brown sugar in each pan around the pineapple slices to create what will be a gorgeous top layer. Finally, sprinkle 2 tablespoons of the chopped walnuts onto the brown sugar.

For the yellow cake mix, follow the box instructions. It will usually call for adding 1 cup water, 1/2 cup canola oil and three eggs. Instead of the water, replace it with the reserved pineapple juice from the can, which is exactly a cup. Mix it all together well into a smooth batter, then evenly divide it among the two cake pans. Bake the pineapple upside down cakes for about 25 to 30 minutes, until golden and toothpick inserted in the center comes out cleanly. Let them cool for half an hour, then turn them out onto cake plates. Serve immediately and enjoy!