This cookie-recipe was unfamiliar for me. You have to beat the eggs and sugar and fold in the dry ingredients into the thick batter. But the batter is extremely tasty and the cookies worked out fine! It gets really dense while chilling, so you can easily spoon it on the baking sheets.
I also used some white chocolate just because I had leftovers - and therefore ended up with "triple" chocolate cookies.
Maybe I should have chilled the dough a bit longer (mine was in the fridge for about four hours) because I had to bake the cookies a bit longer and they cracked as usually cookies do - despite the recipe says they won't. They also didn't firm completely but kept a chewy texture.
But they did taste great and for are really, really great chocolate cookies!
For the recipe for Double Chocolate Cookies, buy the book by Dorie Greenspan and have a look at pp. 329/330!