Preheat oven to 325°F. Line baking sheet with parchment or foil. In large bowl, mix together both flours, cocoa, baking powder, cinnamon, anise, ginger, cloves and salt. Stir in both sugars and nuts.
Using electric mixer on medium speed, beat in eggs and vanilla until soft dough forms. Transfer to board and, using your hands, work last bits of dry ingredients into dough.
Divide dough into two halves. On prepared baking sheet, squeeze and shape each half into a log the length of pan. Flatten each log slightly. Bake until logs are firm and feel dry, about 30 minutes. Cool on baking sheet.
When completely cool, transfer biscotti to cutting board. Using serrated knife, cut biscotti into 1/2-inch-wide slices. Return slices to baking sheet, standing them upright so they are close, but not touching. Bake until dry and crisp, 20 to 30 minutes. Cool completely on baking sheet. Biscotti can be made up to 1 week ahead and stored in an airtight container.