2 cups all-purpose flour
1 teaspoon baking soda
1 teaspoon salt
1 cup (2 sticks) unsalted butter, room temperature
1 cup granulated sugar
1/2 cup packed light-brown sugar
2 large eggs
3 tablespoons instant espresso powder (do not use instant coffee)
2 cups hazelnuts (about 10 ounces), skins removed (see Note below), coarsely chopped
Method
1. Preheat the oven to 375°F (190°C), with racks in upper and lower thirds of the oven. Whisk together the flour, baking soda, and salt in a bowl.
2. With an electric mixer on medium-high speed, cream the butter and both sugars until light and fluffy. Beat in the eggs, 1 at a time, mixing until each is incorporated and scraping down sides of bowl as needed. Beat in the espresso powder.
3. Reduce the speed to low. Add the flour mixture and beat until incorporated. Stir in the hazelnuts with a wooden spoon.
4. Drop heaping tablespoons of the dough 1 1/2 inches apart onto the baking sheets. Bake, rotating the sheets from front to back and top to bottom halfway through, until the cookies are golden, about 12 minutes. Cool the cookies on the sheets for 2 minutes. Transfer to a wire rack to cool completely. Cookies can be stored up to 3 days in airtight containers.
Note: Removing Hazelnut Skins
Preheat the oven to 250°F (120°C). Place the raw (shelled) hazelnuts in a single layer on a rimmed baking sheet. Bake until the skins crack, about 20 minutes. Immediately transfer the nuts to a clean kitchen towel and roll up. Let steam in the towel 5 minutes. Rub the nuts with the towel until most of the skins have come off. (It’s okay if some remain.)