This hybrid dessert is an irresistible cross between apple pie and a fruit crisp. It's easy to make—all you need are six ingredients and you probably already have most of them on hand: butter, light-brown sugar, flour, cinnamon, and lemon juice. Most importantly, you'll need five pounds of tart apples such as Granny Smiths. The apples are sliced and layered with a crumb mixture similar to that used for a fruit crisp. We suggest using a springform pan to accommodate the tall layers.