Preheat oven to 350 degrees F and grease two donut pans with coconut oil or cooking spray.
In a large bowl, whisk together the flour, sweetener, cocoa powder, baking powder, baking soda, and salt. Set aside for later.
In a small bowl, add almond milk, egg, melted butter, and mint extract. Whisk until well combined.
Pour the milk mixture into the dry ingredients and whisk until nicely combined.
Spoon or pipe the batter into the donut pan, filling each cavity around 2/3 of the way full.
Bake for 10 to 12 minutes.
Let cool slightly, then place the donuts on a wire rack to finish cooling.