2 oz. Carbonated Water - (more)
2 oz. Gin - (more)
1 tbsp. Dry Vermouth - (more)
1/2 tsp. Powdered Sugar - (more)
Stir powdered sugar and 2 oz. carbonated water in a collins glass. Fill glass with ice, add gin and vermouth, and stir. Fill with carbonated water and stir again. Garnish with the twist of lemon and an orange slice.