Pastry cream (basic recipe)

In a small saucepan, preferably non-stick, I put the yolks, sugar and vanilla, or the yellow part of the lemon peel. Please do not throw away the egg whites: you can use them for other recipes.

Start whisking until the mixture is pale and fluffy.

Add the flour, mixing thoroughly to remove lumps.

Gradually pour in the milk, which you have heated, and mix thoroughly.

Put on the heat and cook over the lowest heat, never stopping stirring.

You will see the colour gradually change and the cream begin to thicken. Once it starts to simmer, allow about 2 minutes until it is thick and creamy.

Remove from the heat and take out the lemon peel or vanilla pod, if used.
Pour into a container, preferably glass, and spread it out well.

Cover the cream thoroughly with cling film touching its surface. In this way, you will avoid bacterial build-up and prevent a skin forming on top.

Refrigerate; it will keep for 2/3 days.
Remove from the fridge half an hour before using.
You can fill:
Fruit tarts
Layered Pan di Spagna
Cannoncini
Sfogliatelle
Choux buns
And so on.
This is classic pastry cream. Here are some possible variations:
COFFEE PASTRY CREAM
Add a few coffee beans to the milk, replace half the milk with espresso and, if liked, flavour with a tablespoon of cognac.
ZABAIONE PASTRY CREAM
Replace some of the milk, about 50 g, with dry Marsala.
CHOCOLATE PASTRY CREAM
Dissolve a tablespoon of unsweetened cocoa powder or 80 g finely chopped dark chocolate in a small amount of the milk.