Preheat oven to 350°F. Line a baking sheet with parchment paper.
Combine the butter and sugar in the bowl of a food processor and process until smooth.
Add the egg and vanilla and process until smooth. Scrape down the sides with a spatula.
Combine the flour, baking soda, salt and coffee in a small bowl and whisk together. Add the mixture to the processor and pulse until the batter comes together, about 1 to 2 minutes.
Add the hazelnuts and half of the chocolate and pulse until just combined.
Remove the dough from the bowl of the processor; using a spatula, stir until the dough is thoroughly mixed. Refrigerate for 30 minutes and up to 3 days.
Using an ice cream scoop or tablespoon measure, scoop 1 tablespoon of dough for each cookie and place them 2 inches apart on the baking sheet. Top the cookies with the remaining chocolate.
Bake for 10 to 12 minutes, or until golden brown. Transfer to a rack and allow to cool completely.




Preheat oven to 350°F. Line a baking sheet with parchment paper.
Combine the butter and sugar in the bowl of a food processor and process until smooth.
Add the egg and vanilla and process until smooth. Scrape down the sides with a spatula.
Combine the flour, baking soda, salt and coffee in a small bowl and whisk together. Add the mixture to the processor and pulse until the batter comes together, about 1 to 2 minutes.
Add the hazelnuts and half of the chocolate and pulse until just combined.
Remove the dough from the bowl of the processor; using a spatula, stir until the dough is thoroughly mixed. Refrigerate for 30 minutes and up to 3 days.
Using an ice cream scoop or tablespoon measure, scoop 1 tablespoon of dough for each cookie and place them 2 inches apart on the baking sheet. Top the cookies with the remaining chocolate.
Bake for 10 to 12 minutes, or until golden brown. Transfer to a rack and allow to cool completely.