In a medium bowl, whisk together flour, baking powder, baking soda, pumpkin pie spice, cornstarch, and salt until combined. Set aside.
In a large bowl, beat together sugars, coconut oil, butter, pumpkin and vanilla until combined. Add dry ingredients and mix until combined. Gently, stir in butterscotch chips. Cover and refrigerate for 1 hour. If you leave it in longer (ie: several hours to overnight), you may need to let it sit at room temperature for a few minutes before scooping and baking.
Preheat oven to 350. Line two large baking sheets with silpat of parchment papers. Use a small cookie scoop to transfer dough to baking sheet.
Bake until edges are lightly golden and cookies are just set, about 10-12 minutes. Cool completely on baking sheet. Store leftovers in an airtight container for up to one week.
To make vegan or just for a healthier option, replace butter with apple butter. This is how I typically make them, and they come out great!