Did you use a lot of leaf matter in there? That's the only reason I can think of that they would taste funky. I mean, you're going to taste SOMETHING, but if it's as severe as you say maybe there was too much leaf matter (read: chlorophyll) in there. Better luck next time Belledonna, do yourself a favor and take notes on how you made the butter (ratios, how long it cooked, what it looked like etc.) and what you think went wrong with those cookies. Why try and remember it when you can just have it written down?!