1. Preheat oven to 350 degrees. Spray 18 standard muffin cups with nonstick cooking spray.
2. Whisk flour, baking powder and salt in medium bowl. Combine milk and vanilla in measuring cup. Beat sugar and butter in large bowl with electric mixer at medium speed about 3 minutes or until creamy. Add eggs, one at a time, beating well after each addition. Add flour mixture alternately with milk mixture, beating until well blended. Spoon batter into prepared muffin cups, filling about three-fourths full.
3. Bake 18 to 20 minutes or until toothpick inserted into center comes out clean. Cool in pans 10 minutes. Remove to wire rack to cool.
4. Cut off edges of cupcakes to form squares. Cut cupcakes in half crosswise. Spread each bottom half with about 1 tablespoon Nutella or chocolate frosting. Replace tops of cupcakes.
5. Enjoy!