1/2 cup + 1 Tablespoon butter or hard margarine, softened
1/3 cup granulated (white) sugar
3 large eggs
1 teaspoon vanilla extract
1 3/4 cup all-purpose flour
2 teaspoons baking powder
1/4 teaspoon salt
2-3 Tablespoons milk
Nutella, as needed
Preheat oven to 325◦F. Grease or line ten muffin cups with paper liners.
In a large bowl, beat the butter and sugar until light and fluffy. Beat in the eggs, one at a time, beating well after each addition. Beat in the vanilla.
Stir in the next three ingredients, followed by the milk. Divide the batter evenly among the muffin cups, trying to make even, round scoops.
Take a spoonful of Nutella (teaspoon or Tablespoon - as much as you wish) and use another spoon to drop it on top of each muffin. Use a wooden skewer to gently swirl the Nutella through the top of each muffin.
Bake for 20 minutes, or until a toothpick inserted in a part without Nutella comes out clean. These are tastiest served warm!