Preheat oven to 350°F // 180°C. Line baking sheets with parchment paper or silicone baking mat.

In a medium bowl, whisk together flour, baking soda, baking powder, salt, cinnamon, ginger, allspice, nutmeg, cloves and black pepper. Set aside.

In the bowl of a stand mixer, combine butter, sugars and eggs. Mix to combine.

Add vanilla and molasses, mix to combine well. Scrape down bowl.

Add flour mixture and mix until just combined. Remove dough from mixer bowl and divide in half. Using lightly floured hands, form dough into two equal logs roughly 3 inches wide and 12 inches long.

Dust with powdered sugar and bake for 30 minutes, rotating tray halfway through if you do not have a convection oven.

Remove from oven and cool for 10 minutes, or until cool enough to handle comfortably. Transfer biscotti loaf to cutting board and slice into 1/2" slices.

Place biscotti, cut side down, back on baking sheet and bake for an additional 10 - 12 minutes, until crunchy.

Cool on wire rack. After completely cooled, store in airtight container for up to 10 days.