Pastry Cream:

1. Place the gelatin leaves in a bowl of cold water and let sit for 10 minutes.
2. Heat the milk with the vanilla bean, split and scraped, until it boils, then let it steep for 10 minutes.
3. Place the egg yolks, sugar and cornstarch in a large bowl and beat with a hand whisk for 2 minutes until smooth.
4. Remove the vanilla bean from the milk and pour it over the egg yolks while mixing with the whisk.
5. Return the mixture to the saucepan and bring to a boil over medium heat while stirring until the pastry cream thickens. As soon as it starts to boil, extend the cooking time by 2 minutes.
6. Remove from the heat and add the gelatin leaves and mix vigorously to incorporate them.
7. Pour the pastry cream immediately into a baking dish and cover with cling film and place in the refrigerator until completely cooled.

Whipped cream:

1. Place the cold, full-fat heavy cream in a medium bowl.
2. Mix with an electric mixer for about 3 minutes on medium speed until the mixture is stiff like whipped cream.

Diplomat Cream:

1. Remove the pastry cream from the refrigerator and place in a large bowl.
2. Using an electric mixer, blend the pastry cream for 1-2 minutes to loosen it.
3. Add the whipped cream to the pastry cream and mix with a spatula until you have a smooth and firm diplomat cream.
4. Use immediately or place in the refrigerator.