How to Make It
Heat oven to 350º F. Line two baking sheets with parchment.
Whisk together the flour, cocoa, baking soda, cloves, cinnamon, pepper, and salt in a medium bowl. In a separate bowl whisk together the molasses and pumpkin puree.
Beat the butter and sugar in a large bowl with an electric mixer on medium-high until light and fluffy, 2 to 3 minutes. Beat in the egg, scraping down the sides of the bowl as necessary. Reduce mixer speed to low and add the dry and wet ingredients alternately, beginning and ending with the dry ingredients and mixing well between additions. Mix until just combined. Fold in the walnuts and dates.
Drop mounds of the dough (about 1½ tablespoon each) 1 inch apart onto the baking sheets. Sprinkle with the turbinado sugar, dividing evenly. Bake, rotating the sheets halfway though, until firm around the edges, 12 to 14 minutes. Let cool slightly on the baking sheets, then transfer to a wire rack to cool completely.