When I bake a 9x13 cake, I cut it in 4 sections, pop in the freezer until frozen. Then take it out and put each section into a zip lock bag or container, if you have the size. Then back in the freezer. No waste of cake for just two, you don't have to face cake for dessert for a week or more and you can always take out of the freezer at noon, to have dessert for dinner. You can do the same with a layer cake, brownies, etc. I love to section out pie with two pieces to a container, even ones I bring home from the bakery.