From Jay-Z's verse on Beyoncé's "Drunk in Love". although he got it from the movie about Tina and Ike Turner, what he is really doing is saying that Beyoncé eat his ass.
"My girl is hella freaky bruh"
"How?"
"I was all like 'Eat the cake, Anna Mae now eat the cake anna mae!' and the bitch actually ate my ass"
n. When you are baking cupcakes and you put too much batter in the little paper trays causing the cupcakes to rise and fatten during cooking. The result looks more like a butt than a cupcake.