Nutella Swirl Muffins

Here is another Nutella recipe that I made to celebrate World Nutella Day. This simple muffin recipe is featured slightly differently on several different sites. Here is my take on it. In my opinion (as well as the opinion of most Nutella fanatics), with this recipe, the more Nutella, the better! The Nutella swirled on top of these muffins bakes up and makes these self-frosted muffins. 

Nutella Swirl Muffins
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!