Lightly butter 5 x 6cm diameter dariole moulds, lightly buttered. Preheat oven 100C/175F/lowest gas setting.
Next, make the caramel. Pour the 200g sugar into the wide-based pan and set over a medium heat. As the sugar heats it will begin to melt and the sugar will discolour before it caramelises. Stopping the cooking too soon will result in an overly sweet sauce. Try not to stir it. If you must, use a heatproof silicone spoon. A metal spoon will cool the sugar and form a lollypop of caramel.
When ready the sugar will begin to give off a slight blue haze and foam will develop on the surface. Don’t delay now; dip the pan base into a ready bowl of cold water for 2 seconds to stop the cooking.
Pour 1 tablespoon of caramel into the base of each buttered dariole mould. Be careful as it’s scalding hot. Leave to set.
Return the remainder of the caramel back to the heat and add the hot liquid coffee. Some of the sugar will form into lumps as the coffee is added. Slowly stir the mix over a low heat until they have dissolved, then pour the coffee-caramel sauce into a bowl to cool.
Next heat the milk and cream in a small pan. Split the vanilla pod lengthways and gently scrape the inside of the pod with the back of the knife to release the seeds. Add the pod and seeds to the warm cream and milk with the tbsp of espresso. Bring to a simmer then turn off the heat and leave to stand for 5 minutes.
Meanwhile beat the eggs, egg yolk and sugar together. Pour the hot milk mix over the eggs and whisk well.
Arrange the moulds in a roasting tray. Strain the coffee custard into a jug. Fill the moulds with the custard then fill the tray with very hot water to about 2cm from the top of the moulds. Place into an oven at 100C for about 35 minutes.
When ready the custard should be set with a light crust on the surface. Remove to a rack and once cooled enough, place in the fridge. They can be stored for up to 48 hours.
To serve, add the coffee liqueur to the caramel sauce. Turn out the moulds onto cold plates. Pour over the coffee caramel sauce and serve.