Brownie Sludge
The bits of brownie in the bottom of the pan after most or all of the brownies are gone. It is often the gummiest and chewiest and can be formed into a large sized brownie in some cases.
Person 1: "Get your hands out of the brownie pan! There's nothing left in there!"

Person 2: "But I'm making an entire new brownie out of brownie sludge!"