Preheat oven to 350°F (175°C) - Before starting to make the recipe, preheat your oven to 350°F (175°C) and grease a donut pan with cooking spray or butter.

Mix dry ingredients - In a large bowl, whisk together flour, baking powder, salt, granulated sugar, and ground cinnamon until well combined.

Mix wet ingredients - In a separate bowl, whisk together peach cider, egg, and melted butter until well combined.

Combine dry and wet ingredients - Add the wet ingredients to the dry ingredients, and mix just until the ingredients are combined. Be careful not to overmix, or the donuts will become tough.

Fill the donut pan - Spoon the dough into a piping bag or a resealable plastic bag with a corner snipped off. Pipe the dough into each cavity of the donut pan, filling each one about ⅔ of the way full.

Bake the donuts - Bake the donuts in the preheated oven for 12-15 minutes, or until a toothpick inserted into the center of a donut comes out clean.

Make the glaze - In a small bowl, whisk together powdered sugar, ground cinnamon, and milk until smooth.

Glaze the donuts - When the donuts are still warm, dip each one into the glaze until it is fully coated. Place the glazed donuts on a wire rack to cool and set completely.

Serve and enjoy! - Once the glaze has set, serve the Peach Cider Donuts with your favorite breakfast beverage or enjoy them as an afternoon snack.