Cream together the butter and sugar.
Add the egg and milk and mix.
Mix together the flour, baking powder, and salt and add that to the egg mixture.
Add blueberries last and gently mix the fruit into the batter.
Pour batter about ⅔ full into greased or paper-lined muffin tins. (You can sprinkle sugar or a combination of cinnamon and sugar on top of each muffin if desired. )
Bake at 375° for 20 minutes or until done.
I have made this recipe using a half-pint jar of my home-canned blueberries.
I drain them well before adding them to the batter. (And I save the juice to drink later—it’s so good iced or added to 7Up or ginger ale. )