For standard size cupcakes (12 per pan), you could put 2 pans side by side on the middle oven rack for 12 to 17 minutes (time varies for different ovens). To do 325 cupcakes you would have to do 13.5 batches of 24 (approximately 3.25 hours based on 14 minutes per batch of 24). For mini cupcakes the pans are usually 24 per pan. You could put 2 of these pans side by side, therefore your time would be cut in half.