Preheat oven to 350°F (175°C). Lightly grease a mini donut pan.
In a large bowl, whisk together the flour, baking powder, baking soda, salt, cinnamon, and pumpkin pie spice.
In another bowl, whisk together the sugar, pumpkin purée, milk, yogurt, egg, vanilla, and melted butter/oil until smooth.
Add the wet ingredients to the dry ingredients and stir until just combined—don’t overmix.
Put pumpkin donut batter in a piping bag with no tip (or a plain round tip) and pipe the batter into the donut pan, filling each cavity about 3/4 full. Alternatively, you can spoon the batter in, but it gets pretty tricky with mini donuts.
Bake for 8–10 minutes, or until the donuts spring back when lightly touched and a toothpick comes out clean.
Let cool for a few minutes in the pan, then transfer to a wire rack. After mini donuts have cooled completely, start on the chocolate glaze.
If using chocolate candy melts, melt them according to the package instructions. Add a bit of oil to them and mix it in really well to create a texture and consistency that’s a little easier to work with.
If using chocolate chips, melt the chocolate chips and oil together in 20-second intervals, stirring after each, until smooth. If needed, stir in a splash of milk to thin the glaze to your desired consistency.
Dip the top of each donut into the chocolate glaze, letting any excess drip off.
While the glaze is still wet, sprinkle with your favorite Halloween sprinkles
Let the glaze set for about 10 minutes, or pop the donuts in the fridge to speed things up.