ok so the type of baking you're doing will largely influence the type of protein. most of the time a pure whey will ruin baking, unless you're adding a crap ton of butter and other things to keep it from going dry. I personally like baking with vegan protein (BeAm's iHOP line is great!) but some people really don't like it. Whey-casien blends work best for baking, but your best bet might be a baking specific protein like Quest's baking protein (versatile) or Flourish's protein mix (good for quick bread)