Double Chocolate Cookies
1/2 cup all purpose flour
1/2 teaspoon baking powder
1/2 teaspoon salt
12 ounces bittersweet chocolate, cut into larger-than-chip-size chunks
1 stick (4 ounces) unsalted butter
4 ounces unsweetened chocolate, coarsely chopped
4 large eggs, at room temperature
1 1/2 cups sugar
1 1/2 tablespoons instant coffee granules
Whisk together the flour, baking powder, and salt in a medium bowl and set aside until needed. Divide the bittersweet chocolate in half and set half aside.
Place the butter, the remaining bittersweet chocolate, and the unsweetened chocolate in the top of a double boiler over, but not touching, simmering water. (Alternatively, you can use a heatproof bowl positioned over a saucepan of simmering water.) Heat the mixture, stirring occasionally, until the butter and chocolates are melted and smooth. Remove from the heat.
Meanwhile, put the eggs, sugar, coffee, and vanilla in the bowl of a mixer fitted with the whisk attachment and beat at high speed for about 10 minutes until the mixture is very thick and forms a slowly dissolving ribbon when the whisk is lifted and the mixture is allowed to drizzle back into the bowl.
With the mixer on low speed, very gradually add the warm butter-chocolate mixture. Scrape down the sides of the bowl and work your rubber spatula around the bottom of the bowl, then continue to mix just until the chocolate is thoroughly incorporated. Add the dry ingredients and the remaining bittersweet chocolate chunks and mix thoroughly. (You may find it more efficient o finish the mixing by gently folding the ingredients in with the rubber spatula.) The mixture will look like a thick, marshmallowy cake batter.
Cover the bowl and chill for several hours, or overnight. The dough can be made ahead and kept in the refrigerator for up to 4 days.
When you are ready to bake, position the racks to divide the oven into thirds and preheat the oven to 350 degrees. Line two large baking sheets with parchment paper.
Using a heaping tablespoon of dough for each cookie, drop the dough onto the lined sheets, leaving at least 2 inches of space between each mound of dough---these are spreaders. Bake the cookies for 10 to 12 minutes, rotating the pans front to bake and top to bottom halfway through the baking period. The cookies will puff, then sink and crinkle and wrinkle around the edges. These cookies are better underdone than over baked, so if you have any doubts, pull them out of the oven early rather than later. These shouldn't appear dry and they won't be crisp. Use a wide metal spatula to transfer the cookies to cooling racks to cool to room temperature. Repeat with the remaining dough.
The cookies can be wrapped in plastic and kept at room temperature for 2 days or frozen for up to a month. Thaw, still wrapped, at room temperature.
This recipe is from contributor Rick Katz, and can be found on pages 329-330 in Baking With Julia.