Preheat oven to 350 degrees.
Grease a 24-cup mini muffin tin.
Mix together flour, sugar, baking powder, salt, cinnamon, and pumpkin pie spice.
In a separate bowl, mix together egg, buttermilk, and vanilla extract.
Make a well in the dry ingredients; pour in the liquid ingredients. Stir until combined.
Using a cookie dropper, drop batter into each mini muffin cup.
Bake for 9-10 minutes. The donut holes should spring back at you!
Once the donuts have cooled, roll each in melted butter, then roll in the cinnamon sugar mixture.