I am planning on using this cake extender tomorrow http://www.cakecentral.com/cake_recipe-1977-Cake-Mix-extender.html. The thing is I have always used milk instead of water when I make cakes w/ a mix. So, would the milk, with all the other ingredients, make the cake too dense or change it for the worst in anyway?

I always use this extender recipe for my cupcakes and I always substitute whole milk for water with excellent results.

Also, If you want to make chocolate cakes/cupcakes with this recipe add 1 box of instant chocolate pudding to the recipe w/your chocolate cake mix, comes out great!

Good luck!