Ok, found out that no matter how strong I make the coffee, you can't taste it after it's baked! (at least in the chocolate cake mix)I even went over board and nearly used a cup of instant coffee granuals in one mix. Still didn't taste coffee! At that point it started to bake up weird. So, I put 5 Tbs. of instant coffee in a yellow cake mix and it was perfect! All of this experimenting sure does make a house smell good! The coffee flavor comes through well with the yellow and I'm sure the white would do well too. I always liked the yellow for bigger layers. Seems to be moister than the white.