Yield: about 4 dozen mini donuts
In a medium bowl, whisk together flour, baking powder, spices and salt. Set aside. In a another bowl, combine buttermilk and melted butter. Set aside.
In the bowl of a stand mixer, combine brown sugar, sugar, pumpkin puree and eggs. With the mixer on low, add dry mixture in three additions, alternating with buttermilk mixture. Mix until just combined.
Fill prepared pastry bag with batter. Pipe batter into prepared mini donut pans, filling molds a little over half full. Bake for 13-15 minutes until cake springs back to touch. Let cool in pan for 2 minutes before unmolding. Let donuts cool to room temperature on wire rack before glazing.
Cinnamon Glaze: In a small bowl, whisk together confectioners' sugar, cinnamon, maple syrup and milk until smooth. If glaze is too thin, add confectioners' sugar 1 tablespoon at a time. If glaze is too thick, add milk 1 teaspoon at a time.
Dip one side of cooled donut into glaze. Place dipped donut on a wire rack, iced side up. Sprinkle desired toppings over glaze. Let donuts sit until glaze has set, about 10 minutes.