Mickey's Surprise Party

Mickey's Surprise Party is a short that debuted in 1939 at the New York World's Fair as a promotional short for Nabisco. Since then, it has often been edited to genericize the snack products.

Summary
Minnie's biscuits are spoiled when she accidentally gets unpopped popcorn into the dough, and the whole batch explodes. ("It always happened to my mother, too," Mickey helpfully comments.) Luckily, Mickey had biscuits from the store with him all along.