Preheat oven to 350 degrees Fahrenheit and grease two 6-cavity donut pans with non-stick spray.

In a medium bowl, whisk together the flour, baking powder, baking soda, salt, and pumpkin pie spice.

In a separate large bowl, whisk together the pumpkin puree, brown sugar, 0.33 cup granulated sugar, vegetable oil, eggs, and vanilla extract until smooth.

Gradually add the dry ingredients to the wet ingredients and stir with a spatula until just combined.

Transfer the batter to a piping bag with a large round tip or a plastic bag with the corner cut off.

Pipe the batter into the donut cavities, filling each about three-quarters full.

Bake for 10 to 12 minutes or until a toothpick inserted into the thickest part comes out clean.

Cool the donuts in the pan for 5 minutes, then transfer to a wire rack.

In a small bowl, combine the coating sugar and cinnamon.

While the donuts are still warm, dip each side into the melted butter and then immediately toss in the cinnamon-sugar mixture to coat.