1. Preheat oven to 375 degrees. In a large bowl, combine oil, sugars, eggs, and molasses. In a separate bowl, combine flour, whole wheat flour, baking powder, ginger, cinnamon, cloves, nutmeg, and pepper. Slowly add dry ingredients to wet ingredients. Mix until incorporated, being careful not to overmix.
2. Divide dough in half. Form dough into two logs that are 2-inches wide by 12-inches long. Place logs on a parchment-lined sheet pan about 4 inches apart. Bake for 20 minutes, until bottoms are lightly browned and tops are firm to the touch. Remove from oven. Let logs cool for 10 minutes. Reduce heat to 325 degrees.
3. Transfer logs to a cutting board. Using a long, serrated knife, cut biscotti on a 45-degree angle into ½-inch slices. Place slices, cut-side down, on parchment-lined sheet pan. Bake for 5 minutes. Turn cookies over and bake for an additional 5 minutes. Transfer biscotti to a cooling rack.
4. Prepare the icing. Sift confectioners’ sugar into a large bowl. Add water, corn syrup and vanilla and mix well. Put icing in a pastry bag fitted with a small tip or in an airtight bag with a small hole cut in one corner. When cookies have cooled, pipe or spread icing onto bottom of biscotti with an offset spatula. When icing is completely set, store cookies in an airtight container.

Variation

1. Melt chocolate or almond bark in a double boiler or in a heatproof bowl placed over a pot of simmering water. Stir until smooth. Remove from heat. When slightly cooled but still liquid, drizzle over cookies, or dunk cookies into the melted chocolate or almond bark. Place glazed cookies on parchment or wax paper. When dry, store biscotti in an airtight container.
2. Note: All-purpose or almond flour can be substituted for the whole wheat flour.