1Heat oven as directed on box. Place paper baking cup in each of 24 regular-size muffin cups.
2In large bowl, beat cake mix, 2 teaspoons cinnamon, the milk, oil, vanilla and eggs with electric mixer on low speed 30 seconds. Beat on high speed 2 minutes. Divide batter evenly among muffin cups, filling each about two-thirds full.
3Bake cupcakes and cool completely as directed on box.
4Frost cooled cupcakes with vanilla frosting. Sprinkle with additional cinnamon.