TO MAKE THE DONUT HOLES:
Preheat smoker to 350 degrees.
Put the apple cider into a small sauce pan and bring to a boil; reduce to a simmer and let reduce by half.
Let the reduced cider cool to room temperature.
In a large mixing bowl, whisk together the flour, baking powder, cinnamon, nutmeg, cloves, and salt. Set aside.
In a separate bowl, mix together the cool reduced cider, sour cream, brown sugar, vanilla, melted butter, and egg.
Combine the dry ingredients with the wet ingredients and mix until well incorporated.
Evenly distribute the batter into a mini muffin pan and bake for 11-14 minutes OR until you insert a toothpick into the center of the donut holes and it comes out clean.
Transfer to a wire rack and let cool.
TO MAKE THE CINNAMON SUGAR COATING:
Melt the remaining 6 tablespoons of butter and set aside to cool slightly.
In a separate bowl, combine the granulated sugar and cinnamon and whisk until fully incorporated.
Lightly coat the donut holes with the melted butter and toss in the sugar mixture until well coated.