Step 1

Pre-heat oven to 325F/162C.

Step 2

Chop the hazelnuts in a food processor. I pulsed mine about 10 times. Reserve 1/4 of the chopped hazelnuts to sprinkle on top of the cookies.

Step 3

Place softened butter, sugar, and vanilla in a stand mixer and beat on medium high until pale and fluffy (a hand mixer works, too).

Step 4

Add egg yolk and mix again. Be sure to scrape down the sides a few times so everything gets mixed together well and you don't end up with clumps of butter.

Step 5

Sift flour and salt into the cookie batter. Mix on low until just combined.

Step 6

Add 3/4 of the chopped hazelnuts and mix on low until just combined.

Step 7

Using a cookie scoop or your hands, form the dough into 18 balls and place on a prepared cookie sheet. Using a fork, press down on the cookie a couple times (horizontally and vertically) to flatten it out.

Step 8

Sprinkle chopped hazelnuts on the tops of the cookies. You may want to lightly press the hazelnuts into the cookie dough.

Step 9

Bake the cookies for about 12-15 minutes. Check them at 12 minutes and bake longer from there. The cookies are ready when the edges are golden brown.

Step 10

I enjoyed these cookies right out of the oven but I thought they were even better the next day! Store in an airtight container.