Call of the Cutie

A pony earns a cutie mark upon discovering his/her hidden talent or purpose in life. Apple Bloom's concern about her missing cutie mark sparks her to find a way to earn it before an upcoming party. She soon discovers, however, that she may not be the only "Blank Flank" in Ponyville after meeting two other young ponies.
My Little Pony; Friendship is Magic - Season 1, Song #5: "The Cupcake Song"