- Melt the chopped chocolate, half the chips and the butter in the top of a double boiler, over simmering water. Stir until the mixture is smooth and remove the pan from the heat. In a small bowl, whisk the fl our, baking powder and salt to mix. In a mixing bowl, beat the eggs with the sugar until thick and pale in color, about 3 minutes on medium speed. Beat in the espresso powder and vanilla. With the speed on low, fold in the chocolate mixture until well mixed. Add the flour mixture, remaining chips and nuts, if using. Gently blend until well mixed. Heat oven to 350°, allowing batter to rest while oven preheats for 15 minutes or so.
- Drop the batter by heaping tablespoons onto parchment-lined baking sheets about 2 inches apart. Bake in the middle of the oven for 8 minutes. NOTE: Err on the side of underbaking — they are meant to be soft, rich and they will melt in your mouth. If you overbake them, they will be crunchy and, while delicious, they won’t make your eyes roll back in your head.
- Watch them carefully. When they have puff ed, are shiny and cracks are showing top — get them out of the oven. Let cool on the sheet for a minute, then remove them to completely cool on racks. Makes 3 to 4 dozen.
Coating cookies with sugar: Drop a tablespoon of batter into a shallow bowl of powdered sugar and roll the ball around to coat it thoroughly. Move the ball with a spoon (it will be very soft) to a plate. Coat all the balls you want, and when you fi nish the last one, recoat them all again. (Letting the balls sit for a minute lets the second coating really adhere.) As each ball gets a good second coating, move it to the baking sheet and bake as above. One coat of sugar won’t show when they are baked.