Mix all the dry ingredients first
In another container mix the wet ingredients: egg, milk, vanilla and oil
Grease and fill ¾ of your donut pan
Bake at 180°C - 360°F for about 20 minutes
In a skillet over medium heat mix the two ingredients to decorate (butter, cinnamon and sugar substitute) and let a syrup form, decorate your donuts with this and that's it.