The recipe title says it all. These tend to stick a bit in the pan so use foil baking cups.

1/2 cup (1 stick) butter, at room temperature
1 cup granulated sugar (the author says to use
    slightly less if berries are very sweet)
2 large eggs, at room temperature
2 teaspoons baking powder
1 teaspoon vanilla extract
1/4 teaspoon salt
2 1/2 cups fresh blueberries (mash 1/2 cup with fork)
2 cups all-purpose flour
1/2 cup milk

Topping
1 tablespoon granulated sugar mixed with
    1/4 teaspoon ground nutmeg

Preheat oven to 375 degrees F. Line 12 muffin cups with foil baking cups and butter the top of muffin tin.

With electric mixer at medium-high speed, beat butter until creamy. Beat in sugar until pale and fluffy. Scrape sides of bowl. At medium speed, beat in eggs, one at a time. Beat in baking powder, vanilla and salt.

By hand with a wooden spoon, stir mashed blueberries into batter (batter may look curdled). With rubber spatula, fold in half the flour, then half the milk. Add remaining flour and milk, folding in each just until blended. Fold in remaining blueberries.

Scoop batter into muffin cups (cups will be full). Sprinkle with nutmeg sugar. Bake 25 to 30 minutes, until golden brown. Let muffins cool at least 30 minutes in the pan before removing them.

Makes 12 muffins.