chocolate hazelnut biscotti

INGREDIENTS

• 1 cup whole hazelnuts, preferably blanched
• 2 1/2 cups flour, plus flour for work surface
• 1/2 cup Dutch-style cocoa powder
• 1 tablespoon espresso powder
• Pinch of salt
• 1/2 teaspoon baking soda
• 3/4 teaspoon baking powder
• 4 large eggs
• 1 1/3 cups sugar.