I'm making a 12 x 18 sheet cake for this weekend. I made one a few weeks ago, but it seemed like maybe I didn't use enough batter in the pan.

Can anyone tell me how many cake mixes I should use? I usually doctor them with extra flour, sugar, pudding, sour cream, etc..

The 12x18 takes 14 cups of batter, so 3 should do it. Doctoring doesn't seem to make much difference in how much batter my mixes produce, but your recipe may be different. Most mixes produce 4.5 to 5 cups.

Thanks Ali...You always come thru for me....I saw some other info that you had posted about doctoring mixes...Would you use buttermilk in a yellow cake mix? I have regular milk and buttermilk, but not sure how the buttermilk would make the cake taste..What do you think?

Well I can't imagine what I would have said about mixes. I make mostly scratch cakes, my white cake is Earlene Moore's doctored mix. It uses sour cream and no liquid. Since cultured buttermilk is essentially watered down sour cream I think it would turn out really well. It adds a slight tang to cakes that people really seem to like.