Preheat oven to 375˚F . Liberally grease 12 muffin cups or a 12-well muffin tin.
In a large mixing bowl, cream the butter and sugar until they are light and fluffy. Add the eggs, one at a time, beating well after each one.
Mix together the dry ingredients and then add them into the butter/egg mixture, and beat well. Add the vanilla to the milk, then mix that in too, stirring only until smooth. Quickly fold in the berries.
Fill the muffin cups about 3/4 full. Sprinkle the tops with coarse (turbinado) sugar if desired. Bake the muffins about 30 minutes.
Put them on a rack to cool for 10 minutes, then carefully loosen them with a thin and flexible (silicone) spatula. These muffins are very tender and will tear easily!
Remove the muffins to a wire cooling rack, and let cool completely – or stand back and let your family tear into them while they’re still warm.