How to Make It
Heat oven to 350° F. Lightly oil two 6-compartment doughnut pans* (or use 1 pan and bake in batches). Whisk together the flour, baking powder, pumpkin pie spice, salt, and baking soda in a medium bowl; set aside.
In a separate bowl, whisk together the pumpkin puree, granulated sugar, brown sugar, oil, egg, and vanilla. Add the dry ingredients and mix until just combined (do not overmix).
Spoon ¼ cup batter into each compartment of the prepared pans. Bake until the doughnuts are golden brown and spring back lightly when touched, 12 to 14 minutes. Let cool in the pans for 15 minutes, then transfer to a wire rack to cool completely.
Meanwhile, whisk together the confectioners’ sugar, sour cream, and lemon juice in a small bowl. Drizzle over the doughnuts. Scatter on the sprinkles, if desired. Let set before serving.
*You can find doughnut pans ($8 to $20 each) online, in cookware stores, and in some supermarkets. They’re about the size of a muffin tin.