is the link to the cake mix extender recipe. It helps make boxed mixes taste more like "scratch" cakes, and you get slightly more batter from the mix too.
I have not had any trouble with the cake mix extender at all, I've loved the results so far. I always use it with DH mixes.
I've recently started adding 1 T. Merengue powder to help the cakes really rise in the pan too.
The only cake I have trouble with is chocolate. It seems gummy to me when I use the extender.