Pour apple cider into a small pan and cook over medium-high heat until reduced to 1/4 cup. Set aside.
If using a donut maker, preheat. If using a , grease it well with butter, shortening or non-stick baking spray and preheat the oven.
In a medium bowl, whisk together all purpose flour, baking powder, baking soda, ground cardamom, ground nutmeg, ground cinnamon and salt. Set aside.
In a large bowl, whisk together the sugar, brown sugar, buttermilk, 1 tablespoon melted butter and egg. Then whisk in the reduced apple cider.
Mix the dry ingredients into the apple cider mixture, just until combined, don’t over mix.
Spoon or using a piping bag to fill the donut cavities of the mini donut maker or donut pans, filling only about 3/4 full.
Close the mini donut maker lid and cook about 2 minutes. For the mini donut pan, bake 6-8 minutes. A toothpick inserted in the donuts will come out clean when they are done.
Remove donuts to a wire rack and repeat with remaining donut batter.
Melt 3 tablespoons butter in a small skillet. In a medium size bowl, combine granulated sugar and ground cinnamon.
Brush donuts on both sides with melted butter.
Roll donuts in cinnamon sugar mixture and return to the wire rack.
Serve immediately.