Preheat oven to 350°F (175°C). Grease a donut pan.

In a bowl, mix pumpkin puree, granulated sugar, brown sugar, melted butter, vegetable oil, and eggs until well combined.

In another bowl, whisk together all-purpose flour, baking powder, pumpkin spice, and salt.

Gradually add the dry ingredients to the wet ingredients, mixing until just combined.

Pour the batter into the donut pan, filling each mold about ¾ full.

Bake for 14 minutes or until a toothpick comes out clean. Let cool in the pan for a few minutes before transferring to a wire rack.

To make the glaze, melt 4 tablespoons of unsalted butter in a bowl. Whisk in powdered sugar, heavy cream, and vanilla extract until smooth.

Dip the cooled donuts into the glaze and let set on the wire rack.