Preheat oven at 180°C

Place salt, water, sugar (if using) and butter in a saucepan and heat over medium heat, stirring occasionally. 

When the water is starting to boil (butter should be melted at this point), add the flour in one go,and vigorously mix the flour in, so that it absorbs all of the water 

Cook the dough for 1 – 3 minutes (over medium heat) while you mix and move it around in the pan until you get a dough that pulls away from the sides of the pan.

Transfer the dough to a bowl, and let it cool down slightly for a few minutes. Add the vanilla extract (if using), and then with a hand-held mixer (or whisk), mix the dough while adding the eggs one at a time, mixing well after each addition. Make sure the eggs are lightly beaten so that you can stop adding eggs immediately, when you reach the right consistency (i.e. a dough with a glossy sheen with pipeable consistency.

To make the craquelin:
Place the butter, salt and sugar in a bowl and cream the ingredients together until creamy and fluffy.

Add the flour and mix until the mixture looks crumbly. Using your hands, bring the crumbly bits of dough together to form a dough

Roll out the dough until it's about 2-3mm thick. Place on a flat tray and keep in the freezer until completely frozen.

To make the caramel:
Sprinkle the sugar over the surface of a stainless steel pan or non-stick pan.

Heat over medium heat, taking care not to introduce water into the sugar. 

When the color is amber, add the ½ cup of warm cream into the pan. PLEASE STAND BACK AS YOU ADD THE CREAM AT THIS STAGE, because the pan is extremely hot and you don't want splash back. Stir soon after adding the cream, to dissolve the sugar. This will take a few minutes.

 When the caramel has mostly dissolved in the cream, add the rest of the milk, salt, and vanilla into the pan. Heat the milk until it’s nearly boiling, while stirring, to dissolve the rest of the sugar

While the caramel milk is heating, in a separate bowl add the eggs and cornstarch (cornflour), and whisk until you have a smooth mixture.

Add a little of the hot caramel milk in a slow and steady stream to the egg mixture, while whisking the eggs constantly. After adding enough caramel milk to warm up the mixture, pour the egg-milk mixture back into the pan with the rest of the caramel milk

Stir well to make sure the eggs don’t curdle and stick to the bottom of the pan as the custard heats and thickens.

Add the butter to the hot custard and mix until the butter has incorporated into it. Pour the custard into a bowl, and immediately cover the surface with plastic wrap,leave to cool.

Whip the cream and fold in half of the caramel cream.

Take out the craquelin from the freezer and place them on a smooth cutting board. Using a two inch cookie cutter, cut out 2 inch circles from the craquelin (about 22- 24 circles).

Place the choux dough in a pastry bag, which is attached with either a ½ inch round tip or ½ inch French star tip.

Pipe choux pastry mounds on a baking tray line with parchment paper (about 2 inches in diameter). Keep the tip upright and pipe out smooth mounds. Gently twist and remove the tip when you're done. 

Place a disc of craquelin on top and gently press it into the choux to make sure it sticks and is stable. 

Bake in a preheated oven for 30 minutes.

Remove the choux pastries from the oven and allow them to cool for a few minutes

Using a round or star tip, cut out a hole in the bottom of each of the cooled choux pastry cases.

Fill the choux pastries with the salted caramel halfway and finish with the caramel whipped cream.

Dust with some icing sugar and enjoy with a good tea