Preheat the oven to 350◦. Grease a 13 x 18-inch rimmed baking sheet with nonstick cooking spray.
Combine the sugar, oil, eggs, pumpkin, cake mix, and pumpkin pie spice in a large bowl. Using a hand-held electric mixer (start on low and gradually increase to high) or a large whisk, beat the ingredients until fully mixed into a smooth, thick batter.
Spread the batter in an even layer in the prepared pan with a rubber scraper, being sure to smooth the top. Bake until a toothpick inserted into the center comes out clean, about 20 minutes.
Cool completely, then carefully spread the frosting over the top. Cut into bars.
Printed from The Thoughtful Occassion: https://thethoughtfuloccasion.com/recipes/sweet-treats/easy-pumpkin-bars/