boob cake Share definition Flag Boob cake: the way a large set of boobs looks pressed up against the glass of a shower stall, window, ect. "Dude, that chick in the Miata was totally baking me some boob cake" boob cake by spoons, goddamnit! January 16, 2008 0 0 Get merch Get the boob cake mug. Buy Now — $32.95 See more merch