Preheat oven to 325 degrees F. Liberally grease a 20-cavity donut hole pan or mini muffin pan with cooking spray and set aside.

In a large bowl, whisk together the flour, sugars, baking powder, cinnamon, nutmeg and salt. Stir in the apple cider, beaten eggs, oil and vanilla and gently mix to combine. Mixture will still be lumpy; this is normal and do not continue to overmix as it'll lead to tough donuts.

Using a cookie dough scoop, portion batter evenly among the donut hole cavities/muffin tins. Bake for approx. 8-10 minutes or until donuts spring back lightly when touched. Cool in the pan for about 5 minutes, then gently flip onto a wire rack.

Brush the tops and bottoms of the donuts with the melted butter using a pastry brush, then dredge the donuts in the cinnamon sugar mixture, coating completely. Serve immediately, or store airtight for up to 2 days.