In a medium bowl, combine the flour, baking powder, salt, and ADAMS PUMPKIN PIE SPICE. Whisk to blend and set aside. In the bowl of an electric mixer, beat together the butter and sugars on medium-high speed until light and fluffy, 2-3 minutes. Blend in the pumpkin puree. Beat in the egg and ADAMS BEST VANILLA until incorporated. With the mixer on low speed add in the dry ingredients and mix just until incorporated. Cover and chill the dough for at least 1 hour.
Preheat the oven to 350 degrees F. Line baking sheets with silicone baking mats or parchment paper. Combine the sugar and spices for the coating in a bowl and mix to blend. Scoop the dough (about 2 tablespoons) and roll into a ball. Coat the dough ball in the sugar-spice mixture and place on the prepared baking sheet. Repeat with the remaining dough to fill the sheets, spacing the dough balls 2-3 inches apart. Dip the bottom of a flat, heavy-bottomed drinking glass in water, then in the sugar-spice mixture, and use the bottom to flatten the dough balls slightly. Recoat the bottom of the glass in the sugar-spice mixture as needed.
Bake the cookies for 10-12 minutes, or until just set and baked through. Let cool on the baking sheets about 5 minutes, then transfer to a wire rack to cool completely. Repeat with the remaining dough. Store in an airtight container.