What to do? First I scraped the melted mess off the cookie sheets. Then I added approximately the right proportion of the dry ingredients to what was left in the bowl. I mixed it together and put another batch in the oven. Bingo! That worked and they tasted fine. But I still had a bowlful of melted butter, chocolate and walnuts that was just too good to throw away. I added the remaining dry ingredients and sifted another half-batch, then mixed them together. So far, so good, but it was too dry and crumbly. I threw in an egg and a quarter cup of milk. Two tablespoons of milk would have been better but, at this point, I was not quibbling. The dough now looked like chocolate cookies. I threw a batch in the oven and they came out just fine. Tasted good, too.