1/2 cup (1 stick) unsalted butter, sliced thinly into pats
Vanilla ice cream
Preheat oven to 350º F and lightly grease a 9×13-inch baking dish with butter or non-stick spray.
Spread cherry pie filling in an even layer across baking dish.
Spread crushed pineapple carefully on top, then sprinkle all of the cake mix on top of pineapple layer.
Top cake mix with an even layer of butter pats, trying to cover as much cake mix as possible, then top with walnuts.
Place baking dish in oven and bake for 35-40 minutes, or until cake is golden brown and springs back when touched lightly.
Remove from oven and let cool 15 minutes before serving.