It's so simple and only requires a few ingredients that you probably already have in your pantry. Plus, the end result is a fluffy and moist cupcake that's perfect for any occasion.
Preheat oven to 350 degrees F. Line 12-15 muffin cups with paper liners. Will vary a little.
In a large bowl, combine cake mix, 1 cup 7 Up, eggs, and oil. Beat with an electric mixer on low speed until well combined. Raise the speed to medium and beat for 2 minutes.
Fill each muffin cup about two-thirds full with batter. Bake for 18 minutes, or until a toothpick inserted into the center of a cupcake comes out clean.
Frost cupcakes with frosting and serve. Enjoy!
To make the frosting:
In a large bowl, combine butter, confectioners' sugar, and 1/2 cup 7 Up. Beat with an electric mixer on low speed until well combined. Raise the speed to medium and beat for 2 minutes, or until light and fluffy.