Flour Bakery's Double Chocolate Chip Cookies
4 ounces (114 grams) unsweetened chocolate, chopped, +2 ounces (36 grams) finely shaved.
5 ounces (140 g) bittersweet chocolate, chopped, +4 ounces (112 grams) chopped into 1/2 inch pieces
1/2 cup unsalted butter - 1 stick
1/2 teaspoon vanilla extract
1 1/2 cups sugar (300 grams)
1/2 cup unbleached all-purpose flour (70 grams)
1/4 teaspoon baking soda
1/4 teaspoon cream of tartar
1/4 teaspoon kosher salt
1/4 teaspoon instant espresso powder or instant coffee powder
3/4 cup walnuts, toasted and chopped
In a heat proof bowl, combine the 4 ounces unsweetened chocolate, the 5 ounces bittersweet chocolate, and the butter. Place over not touching barely simmering water in a sauce pan and heat, stirring occasionally, until completely melted and smooth. Remove from the heat and whisk in the vanilla. Refrigerate for at least 30 minutes.
Using a stand mixer fitted with the whip attachment or a hand-held mixer, beat together the sugar and eggs on medium speed for about five minutes, or until light, thick, and pale yellow. On low speed, slowly add the chocolate mixture and mix for about 15 seconds. The mixture will not be well mixed at this point, but that's okay. You will finish combining all of the ingredients by hand.
In a medium bowl, stir together the flour, baking soda, cream of tartar, salt, espresso powder, the remaining 2 ounces unsweetened chocolate, the remaining 4 ounces bittersweet chocolate,
and the walnuts. Using a rubber spatula, fold the flour mixture into the sugar butter mixture just until the flour mixture is totally incorporated and the dough is evenly mixed.
For the best results, scrape the dough into an airtight container and let it rest in the refrigerator overnight or for at least 3 to 4 hours before baking. When you are ready to bake, position a rack in the center of the oven, and heat the oven to 350 degrees.
Drop the dough into 1/4 cup balls onto a baking sheet, spacing them about 2 inches apart. Bake for about 15 minutes, or until the cookies are cracked on top and soft but not liquidy when you press them in the middle. Let cool on the baking sheet on a wire rack for 10 to 15 minutes, then transfer the cookies to the rack to cool completely.
The cookies can be stored in an airtight container at room temperature for up to three days. The unbaked dough can be stored in an airtight container in the refrigerator for up to one week.