Heat the oven to 325°F and arrange a rack in the middle. Line two baking sheets with parchment paper, coat the paper with butter, and set aside.
Whisk together the flour, baking powder, baking soda, salt, and cinnamon in a medium bowl, and set aside.
Place the eggs and sugar in the bowl of a hand mixer. Mix on on medium speed until smooth and lightened in color, about 1 minute. Stop the mixer and using a rubber spatula, scrape down the sides of the bowl. Turn the mixer to low speed, add the oil, pumpkin, and vanilla, and mix until evenly blended. Add the flour mixture, and mix until just incorporated. Add in the butterscotch chips and mix until evenly distributed.
Using an ice cream scoop, scoop mounds of the dough onto the prepared baking sheets, spacing the cookies at least 2 1/2 inches apart. Using a thin metal spatula, smooth the tops of the mounds.
Bake the cookies one sheet at a time until the tops feel firm and a toothpick inserted in the center comes out dry, about 16 minutes. Cool them on the baking sheets for 5 minutes, then use a wide metal spatula to transfer the cookies to a wire rack to cool completely. Dust the cooled cookies lightly with powdered sugar.
You can also change this up by adding walnuts, dried cranberries and/or chocolate chips. Of all my cookies these are the most asked for at pot lucks.
I made these, and I can't praise them enough. They are simple, delicious, cakey delights. I followed the recipe exactly, using the ice cream scoop, and they turned out perfectly. I used chocolate chips instead of butterscotch, and added pecans. They were all gone in 2 days!