In a heavy based, medium saucepan, over medium heat, heat 2 cups of the milk and all the sugar, stirring to dissolve until it starts steaming point.

Add the cornflour, eggs and remaining ¼ cup of milk to a medium mixing bowl. Whisk, using a balloon whisk until smooth and combined.

While gently whisking, very slowly drizzle the hot milk into the eggs. Don’t pour it too quickly or you’ll cook the eggs.

Return the custard mixture to the pan.

Stir in the espresso powder, then cook over medium heat, gently stirring with a whisk the entire time until it starts to thicken and bubble.

As soon as you see the first bubbles appear, continue cooking and stirring for a full minute to activate the cornflour.

Remove from the heat and stir in the butter, vanilla and salt until the butter has melted and is fully incorporated.

Pour the coffee pastry cream into a bowl or container, then press plastic wrap to the surface - this will stop it from forming a skin.

Chill to cool completely. You will need to give it a whisk before you use it.

Pastry cream will last for 3-4 days in the refrigerator. NOT suitable for freezing as the mixture can split on thawing.