Does anyone know if I can substitute liquid in the WASC recipe with buttermilk? That would be in addition to the sour cream? Bad idea? Ok idea?

Yes you can! In fact, that's how I make my cakes.

Thank you, Trixie! Do you make any substitutions in any ingredients, or simply sub the liquid for the buttermilk? And, just to clarify, you still use the sour cream, right?