Preheat the oven to 350F. Liberally butter and flour (or baking spray) two – standard (6 wells) baking pans. You will be using 10 wells total.
Combine the flour, pumpkin spice, baking soda, baking powder and salt in a medium bowl and whisk to combine.
1 cup all purpose flour, ¾ teaspoon pumpkin spice, ½ teaspoon baking soda, ½ teaspoon baking powder, ½ teaspoon fine sea salt
Melt the butter in a large bowl. Whisk in the brown sugar until smooth.
¼ cup unsalted butter, ½ cup brown sugar
Whisk in egg, vanilla and pumpkin purée.
1 large egg, 1 teaspoon pure vanilla extract, ¾ cup pumpkin purée
Add the flour mixture, folding with a spatula until just combined.
Fit a piping bag with a large round tip. Fill the bag with the donut batter.
Pipe the batter into 10 cavities of the donut pans. Alternatively, you can spoon the batter into the pans. The cavities should be ¾ full.
Bake the donuts for 9-11, until golden brown, and a toothpick inserted in a donut comes out clean.
Leave to cool on a cooling rack for about 5 minutes before removing them from the pan to cool completely.