Muffins, or other bakery, created from the following ingredients: potato chips, soda, lemon juice, and worms. More generally, a terrible food concoction that makes you sick. Comes from the episode "Applebuck Season" of My Little Pony: Friendship is Magic.
Nurse: It was a mishap with some of the baked goods.
Pinkie Pie: No, not baked goods, baked bads.