Hazelnut Thumbprints

1/2 c unsalted butter, softened

1/2 c plus 2 T sugar

1 large egg, separated, each part lightly beaten

1 tsp pure vanilla extract

1 1/4 c flour

1/8 tsp coarse salt

1/2 c toasted skinned hazelnuts, ground

Nutella, for the filling



Cream butter and sugar together until pale and fluffy, about 3 minutes. Add egg yolk and vanilla, mix well. Add flour and salt, mix until just combined. Refrigerate dough for 2 hours.



Stir together toasted hazelnuts and remaining 2 T sugar in a small bowl. Roll dough into 1-inch balls; dip in egg white, then roll in hazelnut-sugar mixture. Space 1 inch apart on baking sheets lined with parchment paper. Press down center of each ball with your thumb. Bake for :10 min. Remove from oven, press down centers again with the end of a wooden spoon. Return to oven and bake until golden brown, 8-10 min more. Let cool slightly on sheets on wire racks. Fill each cneter with Nutella and then swirl with a toothpick.