When baking a cake, manufacturers of cake-mixes were told, women were acting out symbolically the birth of a child (not for nothing was the vulgar phrase for pregnancy a "bun in the oven"). BNC
"And as my disgusting stepfather walked out two and a half years ago," pointed out Perdita, "the Committee are going to think it pretty odd that Mum's got a bun in the oven." BNC
Called me frigid and said all the other chaps' girls were willing enough, and would it matter all that much if he put a bun in the oven for me? BNC