Fast Light Lemon Mousse

Directions

1. In a large saucepan, combine the sugar and cornstarch; gradually stir in milk until smooth. Bring to a boil over medium heat, stirring constantly. Cook and stir for 2 minutes or until thickened and bubbly. Remove from the heat. Stir in the lemon juice, zest and vanilla.
2. Set saucepan in ice; stir until mixture reaches room temperature, about 5 minutes. Fold in whipped topping and food coloring if desired. Spoon into dessert dishes. Refrigerate for at least 1 hour before serving.