Step 1

Preheat oven to 325°F (160°C). Position rack in the center.

Step 2

Line baking sheet with parchment paper.

Step 3

Spread hazelnuts on a baking sheet and toast in oven for about 12-15 minutes, or until skins begin to crack. Wrap nuts in a kitchen towel for a few minutes. Rub hazelnuts together to remove skin. Let cool and coarsely chop.

Step 4

Increase the oven temperature to 350°F (175°C).

Step 5

In a medium bowl, sift or whisk together the dry ingredients (flour, cocoa, baking powder, and salt). Set aside.

Step 6

In a large mixing bowl, or bowl of electric mixer fitted with paddle attachment, beat butter and sugar until fluffy.

Step 7

Beat in the eggs, one at a time.

Step 8

Add vanilla extract.

Step 9

Add flour mixture to egg mixture; stir with wooden spoon until just incorporated (do not over mix).

Step 10

Fold in chopped hazelnuts and chopped chocolate.

Step 11

Divide dough into quarters. Place each quarter on the cookie sheet, shaping into a log.

Step 12

Bake for approximately 23- 30 minutes or until firm to the touch. Transfer to rack and let cool slightly.

Step 13

Transfer to cutting board.

Step 14

Using a serrated knife, slice cookies at an angle about 1/2 - 3/4 inch thick.

Step 15

Place the sliced cookies back on the baking sheets, and return them to the oven for about another 20-30 minutes (the longer they stay in the oven, the crisper they get). Turn them over at around the 10 minute mark.

Step 16

Remove from oven and enjoy :)