Making an 18x12x2 sheet cake with your yellow cake with pudding, are ingredients adjusted?

Large sheet cakes are an easy way to serve lots of people. You'll want to make two cake mixes. Beat the eggs before mixing in with the mix - it will make mixing the batter a lot easier. Use the same temp and time and check the cake at minimum time. Hopefully your oven is large enough to give lots of air circulation around your large pan. Happy baking!