1 1/2 oz of campari
3/4 oz of dry vermouth
3/4 oz of Ramazzotti (or Amaro)
1/2 oz of Lemon Juice
1 1/2 oz of seltzer water (or sparkling water)
Add all ingredients (except seltzer) to shaker, shake on ice, double strain into highball glass with ice. Top with seltzer water to taste.