Line two large baking sheets with parchment paper or a Silpat mat and set aside.

In a skillet, toast the hazelnuts over medium heat until fragrant, about 3-5 minutes. Pulse in a food processor until finely ground.

In a medium bowl, whisk together the pulsed hazelnuts, all-purpose flour, and Kosher salt.

In a stand mixer, beat the room temperature butter and granulated sugar until light and fluffy, about 3 minutes. Add the vanilla extract.

Gradually add the dry ingredients to the butter mixture, blending until combined. The dough will be moist and slightly sticky.

Wrap the dough in plastic wrap into a ½-inch thick disk and chill for at least 1 hour.

Roll the chilled dough out to a ¼-inch thickness and cut out cookies with a fluted round cutter. Place on lined baking sheets.

Chill the cut-out cookies in the fridge for 30 minutes before baking.

Preheat your oven to 350°F (175°C).

Bake the cookies for 9-11 minutes, or until set and slightly golden. Allow them to cool completely on a wire rack.

Pipe Nutella onto half of the cookies and sandwich with the remaining cookies. Dust with confectioners’ sugar before serving.