In a large bowl stir together brownie mix and pumpkin until fully combined. Spread into prepared pan.
Bake for 27-32 minutes or just until set. They will still appear soft in the center.
Allow to cool completely before cutting.
Notes
If your box of brownie mix is a smaller 16.3oz size, reduce the amount of pumpkin by 3 tablespoons and bake for 25-30 minutes.Leftover brownies will keep in the refrigerator for 3 days.