So I e-mailed Harold McGee, whose book On Food and Cooking can be found in the kitchens of high-class chefs everywhere. It's a fascinating read and an invaluable reference: McGee, who also writes for the Times, eloquently breaks down the science behind the chemical reactions that occur when we prepare food. He would be, I thought, the very person to address the muffin question.
This morning I received a very friendly e-mail from him.
"I would agree with you that this idea is ridiculous," McGee wrote. "If anything fat would rise to the top, since it's less dense than water. And if it did, it would be a badly made muffin from a poorly mixed batter. Chalk up another one for Mitt. Regards, Harold."