Justin Chapple, Food & Wine's resident Mad Genius, uses a Bundt pan to make the ice ring for his delicious rosé-and-rum sangria. Slideshow: More Sangria Recipes
Layer the berries in a Bundt pan. Gradually add just enough distilled water to cover. Freeze until solid, 8 hours or overnight.
In a large punch bowl, stir the wine with the rum, simple syrup, Campari and lemon juice. Refrigerate until chilled, about 45 minutes.
Fill a large bowl with very hot water. Dip the bottom of the Bundt pan in the water to loosen the ice ring and invert it onto a plate. Add the ice ring to the sangria. Serve in wineglasses, with or without ice.
The mixed-berry ice ring can be frozen for up to 3 days. The sangria can be refrigerated overnight.
To make 8 ounces of simple syrup, combine 3/4 cup each of water and sugar in a saucepan. Boil, stirring to dissolve the sugar. Let cool before using.