I was able to find an online recipe converter that helped me figure out the quantities, but I couldn’t find any real hard and fast rules that help me figure out what I need to do to alter the cooking times. One source suggests that when you’re baking an increased recipe in a double size baking pan, “you should drop the oven temperature 15-25 degrees and increase baking time, to allow center to cook without burning edges” On the other hand, the same page says that if you’re cooking multiple pans of the same thing, you should increase the oven temperature by 25 degrees, and allow for more cooking time. But it doesn’t say how much more.