Pre-heat oven to 350° F.In a large bowl, combine flour, baking powder, salt and sugar. Stir in egg, milk, vanilla extract and coconut oil. I add the coconut oil last and stir swiftly, as to avoid it hardening up. Gradually, stir in blueberries.Spoon batter into a liberally greased donut pan (nonstick spray works fine). Divide equally to create 10 donuts- batter should fill donut molds to the center (but not cover it).Bake for 9-10 minutes. Let donuts cool for about 5 minutes before removing them from the donut pan. You may need to use a knife to remove each donut from the pan. Enjoy!