In your widest sauté pan, add the sugar and turn the flame to high and wait. DO NOT STIR - at most, pick up the pan and swish it around to make sure the sugar is evenly melted in the caramel
As soon as almost all of the sugar has turned to caramel turn off the heat
Hold the mould with your oven-mitt-covered hand, or some other protection that will not limit your dexterity yet protect your hand form the hot scalding sugar. With the other hand, pour a little caramel in the bottom and then swirl it around covering the mould internally and on the sides as much as you can
To make the custard
Infuse the milk with the vanilla extract to almost boiling and then remove from the heat and allow to cool. You can do this stage using a large glass measuring jug in the microwave or medium-sized saucepan on the stove-top
In another large measuring jug, whisk the eggs & extra yolk with the sugar
Pour the cooled milk into the egg mixture. Combine well - the resulting consistency will be very liquid
Pour the milk & egg mixture into the caramelized moulds leaving 1 cm/½" space from the top
Cover the moulds tightly with tin foil
Prepare the pressure cooker by adding a couple of cups of water and the cooking rack
Fill the pressure cooker with as many of the filled moulds as possible that will stay level (my cooker only fit 2 of the Le Creuset heart-shaped ramekins at a time). Close and lock the pressure cooker top, turn the heat to high and when it reaches pressure, turn the flame down to minimum
Count 5-8 minutes cooking time (time may vary depending on the size and thickness of the container(s) used)
When time is up, turn off the heat and don't do anything wait for the pressure to come down naturally. If after 10 minutes all of the pressure hasn't released, relieve the rest of the pressure with the pressure valve. For electric pressure cookers, disengage the 'Keep Warm' setting when cooking time is up and turn off or unplug the pressure cooker
When time is up, open the top and check for 'doneness' by sticking a toothpick in the middle of one of the crèmes. If it comes out dirty, simply place the pressure cooker cover back on and wait another 5 minutes - the residual heat from the pressure cooker will keep cooking them. If the crème caramels are still liquid, cook under pressure and additional 5 minutes
Let the crème caramels cool outside the pan for about an hour before refrigerating. Refrigerate for at least 3 hours before serving. If you need to do another batch, remember to add more water in your pressure cooker!
To serve, simply turn each mould upside-down onto separate dessert dishes. If a crème caramel doesn't release on it's own, insert a flat knife and run it carefully along the sides. Then, on one side pull the knife a little towards the centre to break the suction
Replace the dessert plate on top of the mould and flip it over quickly