Ingredients

4 oz. semisweet chocolate, coursely chopped.
1 cup granulated sugar
1 3/4 cups all purpose flour
1/3 cup unsweetened cocoa powder
1 teaspoon baking soda
1/4 teaspoon salt
3 eggs
1 teaspoon vanilla extract
2 1/2 cups coarsely chopped walnuts

Preparation

Preheat oven to 300 F. Line a large baking sheet with parchment paper or waxed paper.
In a food processor fitted with the metal blade, combine the chocolate and sugar and grind until the chocolate is very fine.

Set aside. In a bowl, sift together the flour, cocoa powder, baking soda and salt. Set aside.
In a mixing bowl combine the eggs and the vanilla. Beat at medium speed to blend. Reduce the speed to low, add the chocolate and flour mixtures and mix until a stiff dough forms, adding the walnuts when about half mixed.

Transfer the dough to a floured surface and gather it together. Divide in half. Form each half into a log 12 inches long. Carefully transfer the logs to the prepared baking sheet, spacing them evenly. Pat to even up the shapes. Bake until almost firm to the touch, about 50 min. Let cool for 10 min.

Leave the oven set at 300 F.

Using a spatula, transfer the logs to a work surface. Using a serrated knife, cut on the diagonal into slices 1/2−3/4 inch thick.  Return the slices cut−side down to the baking sheet. Bake for 25 min. Turn the slices over and bake until crispy and dry, about 25 min. longer.
Transfer the cookies to wire racks to cool. Store in an airtight container at room temperature for up to 1 month.

Makes about 2 1/2 dozen