Place four champagne flutes in refrigerator until chill thoroughly.
Meanwhile, take a medium bowl and place 2 cups of good quality softened lemon sorbet in it. Now, whisk it until smooth.
Gradually whisk in 2 tablespoons and 1/3 cup of chilled sparkling wine or Italian Prosecco wine. Again, whisk it with hands until smooth, neither too thick nor thin. Do not whisk it vigorously or too much as too much as it will become too liquid.
Take out the four champagne flutes from refrigerator and equally divide the mixture among them. Top your Sgroppino Cocktails with lemon zest and serve with small spoons.