Begin by boiling the apple cider in a small saucepan over medium heat. Cook until it reduces to about 1/4 cup, roughly 10-15 minutes. Allow it to cool.

Preheat your oven to 350°F (175°C) and grease your donut pan with cooking spray or butter.

In a large bowl, mix together the melted butter and sugar until combined.

Add the egg, Greek yogurt, vanilla extract, and the reduced apple cider to the mixture. Stir until smooth.

In another bowl, whisk together the flour, ground cinnamon, baking soda, baking powder, nutmeg, cloves, and salt.

Gradually add the dry ingredients to the wet mixture, stirring until just combined. Do not overmix.

Spoon the batter into the prepared donut pan, filling each mold about 3/4 full.

Bake in the preheated oven for 12-15 minutes or until a toothpick inserted comes out clean.

While the donuts are baking, melt the remaining 3 tablespoons of butter in one bowl, and mix 1/2 cup sugar with 1 1/2 teaspoons of cinnamon in another bowl.

Once the donuts are done, allow them to cool for about 5 minutes before removing them from the pan.

Dip each warm donut in the melted butter and then coat it in the cinnamon-sugar mixture.