1Heat oven to 350ºF. Place Reynolds Baking Cups in each of 18 regular-size muffin cups. In small bowl, stir together sugar and cinnamon; set aside.
2Make cake batter as directed on box. Fill muffin cups about 1/2 full. Spoon generous 1/4 teaspoon cinnamon sugar onto center of batter in each cup; top cinnamon sugar with the remaining batter divided evenly among cups. In each cup, swirl batter with toothpick to create a spiral effect.
3Bake about 20 to 25 minutes or until toothpick inserted in center comes out clean. Cool in pans 10 minutes; remove from pans to cooling rack. Cool completely, about 30 minutes.
4Place frosting in decorating bag fitted with round tip #20. Starting at outer edge of cupcakes, pipe frosting in spiral pattern, gradually elevating to a peak in center; garnish with pecans.