Make Taco Bowls in a Muffin Tin. I like making muffins, but not every day. (Or even every week.) To justify having a metal muffin tin in my kitchen, I make it work harder for me. For me, that means flipping it over and nestling four warm corn tortillas coated with cooking spray between the cups. After 15 minutes in the oven at 375°F, you’ll have four cute little "taco bowls" that you can fill with your favorite Mexican fillings. It’s cheaper than buying store-bought taco shells, and you don’t have to worry about any unwanted ingredients. Olé!