Preheat oven to 325F and grease a mini muffin pan very well (Use a 24 cavity mini muffin pan).
In a large bowl, whisk together the almond flour, sweetener, protein powder, baking powder, cinnamon, and salt. Whisk in eggs, water, butter, apple cider vinegar, and apple extract until well combined.
Divide the mixture among the wells of the prepared mini muffin pan (you may need to work in batches if your muffin pan only has 12 cavities). Bake 15 to 20 minutes, until muffins are firm to the touch. Remove and let cool 10 minutes, then transfer to a wire rack to cool completely.
In a small bowl, whisk together the sweetener and cinnamon. Dip each donut bite into the melted butter, coating completely. Then roll each donut bite into the cinnamon/sweetener mixture.
Notes
Serves 12.Food energy: 164kcal Total fat: 13.71g Calories from fat: 123 Cholesterol: 42mg Carbohydrate: 4.81g Total dietary fiber: 2.23g Protein: 6.52g Erythritol: 15g