1Heat oven to 350°F (325°F for dark or nonstick pans). Place paper baking cup in each of 24 regular-size muffin cups. In large bowl, beat cupcake ingredients with electric mixer on low speed 30 seconds, then on medium speed 2 minutes. Divide batter evenly among muffin cups. Bake 18 to 23 minutes or until toothpick inserted in center comes out clean. Cool in pans 10 minutes. In 1-quart saucepan, mix syrup ingredients. Heat to boiling over high heat, stirring frequently. Reduce heat to medium; continue to boil 4 minutes, stirring frequently, until slightly thickened.
2Cut a small circle out of the center of each warm cupcake; reserve removed pieces. Slowly pour about 1 teaspoon of syrup into each cupcake hole; replace cake circle. Brush top of each cupcake with remaining syrup. Cool completely in pans, Cover; refrigerate at least 2 hours or overnight.
3Pipe or frost each cold cupcake with whipped cream. Garnish each with fresh mint leaf and quartered lime slice. Store covered in refrigerator.