M.B.
Is there a Whole Foods near you? They make awesome vegan cakes. Or google on-line for a recipe and make your own. Whole Foods and Trader Joe's carry ingredients you would need like cake mixes that are vegan. As for the milk thing, my daughter was breat fed and on formula then went right to rice milk but consumes other dairy products like cheese and yogurt. She has tried cow milk but doesn't care for it.
Best of luck.
M.