When a chick is so overweight that her fat spills out from both the top of her pants (standard muffin top) AND from the bottom of her bra. Also observed in extreme cases as a mushroom fat goiter protruding from the top of a sports bra that is too small.
"Check it out! Helga gained so much weight, she's poppin a Cincinnati Muffin Top!"
"Shit bro, I gotta go wash my eyes out with acid now."