In a medium bowl, whisk together the almond milk and apple cider vinegar. Set aside for 5 to 10 minutes.
In a separate large mixing bowl, or bowl of a stand mixer, combine the gluten-free baking flour, coconut sugar, cinnamon, baking soda, nutmeg, and sea salt. Stir to blend.
To the bowl with the almond milk and vinegar mixture, add the applesauce, maple syrup, and vanilla extract. Whisk until creamy.
Pour the wet ingredients into the bowl with the flour mixture and beat until a batter is formed. Allow the batter to rest at room temperature for 20 minutes.
Meanwhile, preheat the oven to 350 degrees F. Spray a 6- or 8-cavity donut pan with cooking spray.
Spoon the batter into each cavity of the donut pan, filling each one to the top. If you have a 6-cavity donut pan, and you have batter left over, you can bake a second batch.
Bake for 15 minutes, or until the edges are golden brown and a toothpick inserted comes out clean. Allow the donuts to cool in the donut pan for 30 minutes to 1 hour.
Once completely cool, make the coating. In a medium mixing bowl, whisk together the powdered monk fruit, almond milk, and vanilla extract until smooth and creamy. In a separate small bowl, blend the coconut sugar and cinnamon.
Dip each donut in the monk fruit glaze and set on a cutting board or plate. Sprinkle with the coconut sugar and cinnamon mixture if desired. Enjoy right away, or allow the coating to set in the refrigerator for 1 hour. Store coated donuts in the refrigerator for up to 1 week.