This Aperol Spritz contains rum, Aperol, rum, and grapefruit juice, whereas a Garibaldi Cocktail consists of Campari, another classic Italian bitter liqueur, and orange juice. Both are bittersweet cocktails, but an Aperol Spritz is slightly sweeter and less bitter than a Garibaldi Cocktail. If you want to keep the integrity of the Aperol Spritz but add a bit more bitterness, swap out the Aperol for Campari!