Heat your oven to 300°F (150°C) and position the rack in the middle of the oven. And boil water in a large pot for later use.
Slice the vanilla bean lengthwise and scrape out the seeds.
Whisk egg yolks in a bowl for a minute and set aside.
In a saucepan, gently heat the heavy cream, sugar, vanilla seeds, and pod. Whisking constantly so it doesn’t burn on the bottom.
Once the mixture simmers at 205°F (96°C) avoid boiling, remove from heat immediately.
Very, very gradually, add some of the cream mixture to the beaten egg yolks while whisking the egg yolks constantly. Do this until all of the cream is added.
Strain this mixture through a fine sieve into a large bowl to catch the vanilla pod and any solids.
Pour the strained cream into a 9x9 inch baking dish and place it inside a larger roasting pan.
Add the boiling water to the roasting pan, halfway up the sides of the baking dish, avoiding the cream mixture.
Bake for 40 minutes, then cover with foil and bake for another 20 minutes. The center should be slightly jiggly.
Cool on a wire rack for 2 hours, then, cover it with plastic wrap and place it in for at least 4 hours to set, or overnight is best.
For assembly, take the cream out of the fridge whisk the set cream until smooth.
In your serving glasses, layer crushed cookies, cream, about 2 tablespoons of raspberry jam, more cookies, and cream.
Sprinkle a generous layer of sugar on each trifle making sure it goes all the way to the edge and fully covers the cream, and torch it until browned.
Let it sit for a few minutes for the sugar to set before serving.