No, you won’t double the bake time, but you might need to keep your desserts in a little longer to account for the extra pan in the oven. Check for doneness at the original bake time, then keep an eye on it in 3-5 min increments until it’s ready. When using multiple bake pans, make sure one isn’t cooking faster than another or is in a hot spot in your oven. You might want to rotate the pans or switch them to another rack halfway through your bake time.