Preheat oven to 350°F. Lightly grease a mini muffin tin. Set aside.
In a medium bowl, whisk together flour and next 6 ingredients (to cloves).
In a large bowl, whisk together the Greek yogurt, canola oil, pumpkin, brown sugar, egg, vanilla extract, and milk.
Stir the flour mixture into the Greek yogurt-pumpkin mixture. Only stir until it's just combined; do not over-mix.
Scoop batter into mini-muffin tin - about 2 tablespoon batter in each.
Bake for 10-12 minutes, until they are slightly golden and aren't mushy when you lightly touch them.
While they are baking, melt the butter. In a small bowl, stir together the 6 tablespoon sugar and 1 tablespoon cinnamon. Set aside.
When they come out of the oven, transfer about half of the "doughnut holes" to a large bowl {with a lid} or a brown paper bag or large zip-top bag.
Pour some butter over them, gently shake to coat all doughnut holes with butter. Then sprinkle on about 5 or 6 spoonfuls of cinnamon-sugar. Shake to coat. Transfer coated doughnut holes to plate or cooling rack.
Repeat with remaining doughnut holes. Try not to eat all 32 at once. Keep them covered in the refrigerator.