Preheat the oven to 400?F.

In a medium bowl, whisk together the flour, baking powder, salt, and cinnamon.

In another bowl, mix the melted butter with the apple cider, sugar, and egg. Add this to the dry ingredients until just combined. Do not overmix.

Spray a doughnut pan or muffin tin with cooking spray. Carefully spoon the batter into the pan.

Bake for 7-10 minutes, or until a toothpick inserted in the center comes out clean.

Let cool for 1-2 minutes before removing from the pan.

Pour the remaining melted butter into a shallow bowl. In a separate bowl, stir together the sugar and cinnamon. While the doughnuts are still warm, dip each one in the butter on both sides, then roll in the cinnamon sugar until fully coated.