Remove butter from the fridge and bring to room temperature.
In a medium bowl, combine 3 3/4th cup flour, 1.5 teaspoons baking powder, 1/2 teaspoon salt, and 1 teaspoon pumpkin spice. Whisk to blend and set aside.
In the bowl of an electric mixer, beat together the butter and 1 cup granulated white sugar, and ½ cup light brown sugar on medium-high speed until light and fluffy, 2-3 minutes.
Blend in the 3/4 cup pumpkin puree.
Once pumpkin is well mixed in add the egg and vanilla extract and mix 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˚ F.
Line baking sheets with silicone baking mats or parchment paper.
Combine the sugar and pumpkin spice for the coating in a bowl and mix to blend.
Scoop the dough 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.
Press the balls down and sprinkle the sugar mixture on top.
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.