Preheat oven to 350 ℉. Lightly grease 15 muffins cups or line them with paper liners.
Whisk together the gluten-free flour blend with the baking powder and salt in a small bowl. Set aside.
In a large bowl, combine butter and granulated sugar. Beat on medium-low speed until thick. With the beater still running, add the eggs. Beat until combined.
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.
Spoon 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.)
Allow 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.
This recipe has not been tested with other flour blends. For the best results, use the flour recommended.