Double Dark Chocolate Hazelnut Cookies

Preheat oven to 325 degrees F (165 degrees C). Line 2 baking sheets with parchment paper.

Beat butter in a large bowl with an electric mixer until light and fluffy. Add sugar and salt; beat until combined. Beat in egg and vanilla extract until well-blended. Blend in melted chocolate, cocoa powder, and espresso. Mix in flour gradually, until batter is smooth. Fold in chocolate chips, chopped hazelnuts, and ground hazelnuts.

Drop heaping tablespoons of cookie batter 2 inches apart onto baking sheets. Use the back of a wet fork to flatten each cookie slightly, making a crisscross pattern.

Bake in the preheated oven until set and edges start to darken, about 15 minutes. Let cool a few minutes before serving.