Combine the Campari and syrup and shake with ice. Evenly distribute between 4 ice-filled glasses and top each with seltzer and a pinch of sea salt. Stir gently to combine and garnish.
Vanilla-Orange Zest SyrupCombine ingredients in a saucepan over medium-high heat and bring to a boil. Reduce heat and let simmer for 30 minutes. Strain, and measure the remaining liquid; add an equal amount of sugar while the liquid is still hot, and stir until sugar dissolves. Cover and keep refrigerated for up to 2 weeks.
TipThe vanilla-orange zest syrup also makes a great base for alcohol-free sodas. Simply pour 1 1/2 to 2 oz. over ice, top with seltzer and stir.
