Beat 2 sticks butter, 3/4 cup dark brown sugar and 3/4 cup granulated sugar until fluffy; beat in 1 teaspoon vanilla and 2 eggs. Whisk 2 1/2 cups flour, 3/4 teaspoon baking soda and 1 teaspoon salt, then stir into the butter mixture. Add 2 cups dark chocolate shavings and 2 cups chopped pecans. Pat into a rectangle on parchment paper and chill 1 hour. Cut into 2-inch squares and freeze 30 minutes, then bake 14 to 16 minutes at 350 degrees.
Make Classic Chocolate-Chip Cookie dough (No. 11) with 2 cups dark chocolate shavings instead of chips. Add 2 cups chopped pecans. Pat into a rectangle on parchment paper and chill 1 hour. Cut into 2-inch squares and freeze 30 minutes, then bake 14 to 16 minutes at 350 degrees.