Add cinnamon sticks and apple cider to a small pot. Bring to a boil and simmer on low until reduced, about 15-20 minutes. Remove cinnamon sticks and measure out 1/2 cup of the apple cider. Refrigerate to cool.

Combine milk and vinegar, stir and let sit 5 minutes.

Pre-heat oven to 350 degrees and spray donut pan with non-stick spray.

While the cider is cooling, sift flour, xanthan gum, baking powder, baking soda, cinnamon, cloves and salt in a large bowl. Whisk to combine and set aside.

In a medium bowl, whisk together egg, brown sugar, 1/2 cup granulated sugar, 2 tablespoons melted butter and the vanilla extract in a large bowl. Whisk in milk/vinegar and the cooled 1/2 cup of apple cider.

Add the wet ingredients into the dry ingredients and stir until just combined. DO NOT over mix. Batter will be slightly lumpy.

Pour batter into donut pan and fill about 3/4 of the way full. Don't over fill! Bake (in batches if necessary) for 10 minutes. Remove donuts from donut pan and cool slightly on a wire rack.

While the donuts are baking/cooling, combine sugar and cinnamon for the topping in a shallow bowl wide enough to dip the donuts in and melt the 4 tablespoons butter.

Lightly dip slightly cooled donuts in the butter and then immediately dip them in the cinnamon/sugar. Turn in sugar until completely coated and place on a wire rack. Repeat with each donut. Enjoy warm or at room temperature!