Creating both pudding and mousse can be straightforward if you follow these steps:

Pudding Instructions

1. Combine Dry Ingredients: In a saucepan, mix together sugar, cornstarch, and salt.
2. Add Milk: Gradually whisk in the milk until smooth.
3. Heat Mixture: Cook over medium heat, stirring constantly until it thickens and starts to bubble.
4. Remove from Heat: Once thickened, remove from heat and stir in vanilla and butter.
5. Cool: Pour into serving dishes and let cool for at least 30 minutes before serving.

Mousse Instructions

1. Prepare Gelatin (if using): In a small bowl, sprinkle gelatin over water and let it bloom for about 5 minutes.
2. Whip Cream: In a mixing bowl, whip heavy cream until soft peaks form, then set aside.
3. Beat Egg Whites: In another bowl, beat egg whites until soft peaks form, gradually adding sugar until stiff peaks form.
4. Incorporate Gelatin: If using, gently heat the bloomed gelatin until dissolved, then mix into the egg whites.
5. Fold Mixtures: Gently fold the whipped cream into the egg white mixture until combined.
6. Chill: Pour into serving glasses and refrigerate for at least 2 hours before serving.