Put coconut flour, salt and baking powder into a big mixing bowl. Mix with a hand mixer the butter, cream cheese, sweetener and extracts. Add the coconut flour mixture to the wet ingredients. Mix well. Add the eggs to the batter and mix slowly until completely combined. Gently fold in with a spatula the blueberries. Spray a muffin tin with oil spray. Put an ice cream scoop of batter into each muffin cup. This makes enough for 24 muffins. Preheat oven to 350 degrees. Bake muffins for 25 to 30 minutes until the tops are golden brown. Take out of oven. Take the muffins out and place on a plate. Serve with salted butter.