If you're going to bake an Apple pie from scratch, first you must invent the universe. But before that, buy a high dimensional superluminally expanding hyper oven.
Just use a spherical oven and perform a geometric inversion with origin the centre of the oven and radius the oven's radius. Then all the pie inside will become outside and the outside will fold inside and you'll have infinite space for pie. As easy as capturing a lion.
You just broke my brain.