Hubby likes those big chocolate cakes from Costco. I like their apple pies. Hubby doesn't like cooked apples and I can't eat gluten/wheat so if we buy either the cake or the pie, one person would have to eat the whole thing before it goes bad (I don't eat the crust of the pie). That simply isn't possible.
So, I do as above. I slice what is left into serving size pieces. I put those on a cookie sheet. I stick the cookie sheet in the freezer. I let the pieces freeze then I pop them off the cookie sheet, double wrap them and put them back in the freezer. When I want to defrost one, I unwrap it, put it on a plate, gently cover it with plastic wrap and put that in the frig or on the counter to defrost. Sometimes hubby can't wait for a slice of chocolate cake and will microwave it. Freezing the cake before wrapping and unwrapping it before defrosting works particularly well because then the decorative frosting doesn't stick to the plastic wrap and get messed up.