Preheat the oven to 150 ° C. Put the egg yolks separately in a large bowl and set aside. In a saucepan over medium heat, bring the brown sugar and butter to the boil without stirring until the sugar turns a deep amber color and develops a nutty odor (approx. 10 to 15 minutes). Very slowly stir the cream into the mixture, stirring constantly. Remove from heat and add the salt and scrape the kernels from the vanilla pod into the mixture. Stir the entire mixture to combine the ingredients.
Let rest for 5 minutes. This step is extremely important, the butterscotch mixture must not be too hot otherwise scrambled eggs will be created immediately when stirred into the egg yolk. Slowly add the butterscotch mixture to the egg yolks and stir. Put the pudding through the sieve in a measuring cup.
Pour the mixture evenly into the casserole molds and distribute them. Cover the molds with aluminum foil. Put boiling water in a baking sheet pan so that the molds can stand up to half covered in the water and place in the middle of the oven. Place the molds in the water bath and bake for 45 minutes.
Then turn it 90 degrees and bake for another 15 minutes. Carefully remove the puddings from the water bath with tongs and cool in the refrigerator. Bring to room temperature before serving.