Preheat the oven to 350 degrees F. Spray two standard doughnut pans with floured cooking spray; set aside.

In a large bowl, combine pumpkin, sugars, butter, oil, and eggs. Use a hand mixer to beat until well combined.

In another medium bowl, whisk together flour, baking powder, pumpkin spice, and salt. Mix dry ingredients into wet ingredients until combined.

Fill the wells of the doughnut pans about 3/4 full, using about 1/4 cup of batter in each well. If desired, transfer the batter to a large zipper bag, cut one of the corners off, and pipe the donuts for less mess. Gently tap pans against the counter to smooth out the batter.

Bake for 14-16 minutes, or until a cake tester inserted into the center of one comes out clean. Remove from oven and allow to cool in pans for 5 minutes, then transfer to a wire rack to cool.

While the donuts are cooling, melt 4 tablespoons of butter in a small saucepan over low heat for 5-7 minutes until browned.

Pour browned butter into a small bowl. Whisk in powdered sugar, cream, and vanilla until completely smooth, returning to heat to further melt sugar if necessary.

Dip donut tops in glaze and return to cooling rack to dry.

Store leftover donuts covered at room temperature for 3-4 days.