Add the cream, caster sugar and vanilla to a saucepan or large pan.
Heat on medium heat until the cream is just about to boil.
In a bowl, add the egg yolks and whisk together very briefly.
Pour 1 ladle of hot cream onto the egg yolks and whisk well.
Pour the hot egg yolks into the saucepan with the hot cream and whisk immediately until well combined.
Place a sieve of chinoix over a large mixing bowl and pour the brulee base through the sieve to remove any egg yolk.
Place cling film directly on to the brulee mix surface to prevent a skin forming.
Allow the mix to cool down at room temperature. Once cooled, place into the fridge overnight or for at least 4 hours to completely cool.
Preheat oven to 120°c (240°f) or 110°c (220°f) if fan assisted.
Once the mix has completely cooled. place 1-2 tbsp of roasted plums into the base of each ramekin.
Remove the brulee mix from the fridge, remove the cling film and whisk together. Transfer into a jug for eacsy pouring.
Pour the brulee mix into each ramekin, on top of the roasted plums until they are about 4/5 full.
Carefully place the ramekins into a deep tray and pour water into the tray, taking care to avoid splashing any into the ramekins to about 1/2 the height of the ramekins.
Bake for 50-60 minutes until the brulees have set. This means that if you carefully jiggle the tray, they should not appear liquidy.
Remove from the oven once cooked. Allow to cool for 5 minutes before carefully removing the hot brulees from the water. Place onto a cold or room temperature tray or surface and allow to cool slightly.
Once the brulees are cold enough to place into the fridge, cover each with a small piece of cling film and place into the fridge overnight or for at least 4 hours.
Once the brulees have all cooled completely, remove from the fridge.
Sprinkle 1 tsp of white caster sugar over each brulee and using a blow torch, melt and caramlise the sugar all over the top. To help spread the sugar, you can tilt the ramekin as you burn the sugar. Be careful not to burn your fingers while doing this.
Serve immediately once you have caramlized the sugar.
Un baked brulee mix can last for up to 3 days in th fridge in an airtight container, as can the baked brulees, before the sugar topping.