Combine sugar, brown sugar, cornstarch, salt, and ground cinnamon in a heavy saucepan. Mix beaten eggs with 1/2 cup milk and add to remaining 2 cups of milk. Add milk mixture and butter to dry ingredients. Blend well and cook over medium heat, stirring constantly until mixture comes to a boil. Cook for 1 minute.
Remove from heat; add extracts. Blend well and pour into individual pudding cups or footed sherbets.
Refrigerate at least 1 hour. Top with whipped topping. Garnish each with a sprinkle of cinnamon, if desired.