Recipe from: MarthaStewart.com
2 cups all-purpose flour (spooned and leveled)
1 teaspoon baking soda
1 teaspoon salt
16 tablespoons (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
2 cups (about 10 ounces) hazelnuts, skins removed, coarsely chopped
Preheat oven to 375 degrees. In a medium bowl, whisk together flour, baking soda, and salt. Set aside.
With an electric mixer, beat butter and sugars until light and fluffy. Beat in eggs, one at a time, beating after each addition. Beat in espresso powder.
With mixer on low speed, beat in flour mixture until incorporated. With a rubber spatula or wooden spoon, mix in hazelnuts.
Drop heaping tablespoons of dough onto three baking sheets, 1 1/2 inches apart. Bake, first two sheets together, until golden, about 12 minutes, rotating sheets front to back and from top to bottom halfway through. Repeat with remaining sheet. Cool cookies on sheets 2 minutes; transfer to a wire rack to cool completely. Serve, or store in an airtight container up to 3 days