I wanted to bake this today, and had only pineapple chunks. I placed pineapple in my blender and ran a short time to "make" crushed pineapple. I added the cranberry sauce to blender and ran again very short time to mix. It was delicious, and I knew this was going to be good! IT IS! Like any dump cake, it's more like a cobbler than cake. We topped with a bit of whipped cream.
Preheat oven to 350. Spray 13 x 9 inch baking pan with nonstick cooking spray.
Mix pineapple and cranberry sauce together, stirring until mixed well. and pour into prepared pan. Top with cake mix, spreading evenly. Pour butter over top of cake mix, covering cake mix as much as possible.
Bake 50-55 minutes or until toothpick inserted into center of cake comes out clean. Cool at least 20 minutes before serving.