Prepare Wet Ingredients: In a large bowl, cream together the softened butter, granulated sugar, and brown sugar until light and fluffy. Beat in the egg, vanilla extract, and pumpkin puree until just combined.
Combine Dry Ingredients: In a separate bowl, whisk together the flour, baking powder, baking soda, salt, cinnamon, and pumpkin pie spice.
Form Dough: Gradually add the dry ingredients to the wet ingredients, mixing until a dough forms. Fold in the butterscotch chips.
Rest Dough: Let the cookie dough rest for 10 minutes.
Bake Cookies: Preheat your oven to 350°F (175°C). Lightly spray a baking sheet with cooking spray.
Using a 1-ounce scoop, drop about 8 cookies onto the prepared baking sheet. Gently press each cookie with your finger and lightly dust with powdered sugar.
Place the baking sheet on the top rack of your oven and bake for 10-12 minutes, or until the edges are lightly golden.
Cool and Repeat: Remove the cookies from the oven and transfer them to a wire rack to cool. Repeat the baking process with the remaining dough until all cookies are baked.