Preheat oven to 350 degrees F. Line 2 muffin pans with about 18 paper liners; set aside.
In a large bowl, combine the cake mix, eggs, oil, vanilla creme soda, brown sugar and dry pudding mix. Beat with an electric mixer for about 2 minutes or until combined. Portion the batter evenly among the muffin cups, filling about 3/4 full.
Bake the cupcakes for approx. 15-17 minutes or until a toothpick inserted near the center comes out clean or with moist, not wet, crumbs. Cool completely.
In the bowl of a stand mixer, combine the butter, butterscotch sauce, brown sugar, butter and vanilla extracts with the paddle attachment until creamy, about 30 seconds. Add in the powdered sugar, one cup at a time, until frosting is light and fluffy, streaming in the heavy cream if needed (if frosting is too thick).
Pipe the frosting onto the cooled cupcakes. If piping the frosting as high as in my photos, you may want to double the recipe. Drizzle with caramel or butterscotch sauce.