Preheat oven to 300 degrees F. Cream the butter with the sugars on medium-high speed until fluffy, about 30 seconds. On medium speed add the egg and vanilla and beat about another 30 seconds.
In a separate bowl, sift together the flour, baking powder, baking soda, salt, and 6 tsp. pumpkin pie spice mix; with the mixer running, add to the butter mixture and mix for several minutes until well combined, scraping down the bowl.
In a large bowl, mix the 1/2 cup sugar and 2 tsp. pumpkin pie spice mix; stir well to combine. Scoop balls of cookie dough (about 2 tablespoons—I use a #40 scoop), roll into balls, and drop about 4 at a time into the sugar-pumpkin spice mixture. Roll the cookie balls to coat in the sugar mixture.
On a parchment-lined baking sheet, place cookie dough balls at least an inch apart and press to about 1/4” thick with the flat bottom of a glass. Bake cookies, checking after about 14 minutes, until nicely browned around the edges but still slightly underdone in the middle. The cookies will come out chewy rather than crisp. Let cool on the baking sheet 3-5 minutes, then slide them off with the parchment paper to cool.