Hello
If I need 2 boxes of cake mix will it be okay if I just mix the boxes together or do they need to be mix 1 at a time?

I mix boxes all the time and never have a problem. Happy baking!!

Thanks teasom do you know how many boxes I need for the 9x13 pan

mix them together, I have done it seperately and sometimes the color looks a little different, it tastes ok but looks funny when you cut into a layer cake with two different shades.

I mix boxes as well.....you only need 1 box for the 9 by 13. I like to use the extender though for a nice full,tall cake.

for a 9x13 cake you need 7 cups of batter. that would be 1 + cake mixes. while 1 cake mix will make a 9x13 cake,the 7 cups of batter makes a thicker more level cake........