This light and refreshing citrus dessert really sparkles.
Combine gelatin and 1/4 cup club soda in a small bowl; let stand. In a saucepan, heat lemon juice and sugar over medium, stirring until sugar is dissolved. Remove from heat; stir in gelatin mixture until dissolved.
Transfer to a bowl; stir in remaining club soda. Refrigerate until set, about 5 hours. Serve with whipped cream and zest.