One rule: every plate exact, nothing left
Tap a cake to place a knife: the cut snaps to the cake's lines, no precision needed, then press CUT. One knife = one cut = one piece split in two. Knives are counted. Slide whole pieces onto the plates: a plate turns gold when it is exact, soft red when it gets too much. Unlimited Undo (an undone cut gives its knife back), free restart, no timer during levels, no game over.