AI'm planning to bake a cake using a 11x15 pan and The recipe I've been using is for a 9x13 pan. Would I need to double or triple my recipe? What about for the frosting?

Thanks in advance. :)

The 11x15 pan if you fill it up two inches with cake mix would have a volume of 330 in3 and the 9x13 has a volume of 234 in3 so doubling it will be more than enough. Honestly, you can just do it with area 165 in2 vs 117 in2. The bigger pan is not twice as big as the smaller one.