Yes, you can cook this mug cake without a microwave; however, it takes longer. Follow the mixing instructions of the recipe but, instead of transferring the batter to a coffee mug, transfer it to a cupcake pan or oven-safe ramekin. Place the cake in the oven at 350 degrees for about 10-12 minutes, checking for doneness as you would with a full-size cake using a toothpick. Insert a toothpick into the center of the cake and check for cleanliness; it’s done if it comes out clean.