Recipe for Coffee and Hazelnut Cookies

In a bowl, cream the softened butter with the powdered sugar until well combined. Add the whole egg and instant coffee (mix well), then gradually incorporate the sifted flour and ground hazelnuts. Work the dough a little (add a bit of flour if necessary). Form a ball, wrap it in plastic wrap, and place it in the refrigerator for at least 30 minutes.

Preheat the oven to 180 degrees. Roll out the dough on a floured surface. Cut shapes using a cookie cutter or a small glass. In a bowl, whisk the egg yolk with the vanilla sugar and a few drops of liquid coffee.

Place the cookies on a baking sheet lined with parchment paper. Brush the cookies with the mixture of egg yolk, vanilla sugar, and coffee. Bake the cookies in a moderate oven for about 10 minutes (depending on their size).

To finish, when removing from the oven, place the cookies on a baking rack and let them cool before enjoying.