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Inside a two-dimensional region (``cake''), there are nonoverlapping tiles of a certain kind (``toppings''). We want to expand the toppings while keeping them nonoverlapping, and possibly add some blank pieces of the same “certain kind,” such that the entire cake is covered. How many blanks must we add? We study this question in several cases: (1) The cake and toppings are general polygons. (2) The cake and toppings are convex figures. (3) The cake and toppings are axis-parallel rectangles. (4) The cake is an axis-parallel rectilinear polygon and the toppings are axis-parallel rectangles. In all four cases, we provide tight bounds on the number of blanks.