2 cups orange juice, plus more for ice float
2 cups pineapple juice, plus more for ice float
1 cup fresh lemon juice
1 cup Grapefruit White Balsamic Vinegar
2 cups white rum
1 cup St-Germain elderflower liqueur
1 ruby red grapefruit, thinly sliced
1 lemon, thinly sliced
1 bottle brut prosecco
24-ounces Sparkling Water
In a large lidded container, stir together orange juice, pineapple juice, lemon juice, Grapefruit White Balsamic Vinegar, rum, and St-Germain. Refrigerate overnight.
In a 6-inch bundt pan, place alternating slices of grapefruit and lemon along the bottom. Reserve any remaining slices for punch bowl. Fill bundt pan halfway with orange and pineapple juice and place in freezer. When frozen enough for fruit to stay in position, fill to the top with juice and freeze overnight. When ready to serve punch, set bundt pan in a warm water bath until ice float can be removed. Pour punch into a clear glass bowl, then top with reserved citrus slices and ice float. Add prosecco and soda, stir lightly, and serve.