Add the dry ingredients and mix on low speed. Mix until thick. Stop the mixer and add the milk and vanilla extract. Mix until a thick batter forms.
05Gently fold in the blueberries with a rubber spatula.(If you are using frozen or cold blueberries, the batter will get VERY thick. This is totally normal.)
06Spoon batter into prepared muffin pans. Fill each cavity about ⅔ full. Top each muffin with about 1 teaspoon of granulated sugar. (The sugar topping is optional.)
07Bake until a cake tester inserted into the center of one of the muffins comes out clean, about 25 minutes.
08Allow muffins to cool in the pan for five minutes and then transfer to a wire rack to cool completely.Store the cooled muffins covered on the counter. They’ll keep for about three days.Or you can freeze them. Place the muffins in a freezer bag and freeze for up to two months. Allow the muffins to thaw at room temperature.