Warm vanilla bean for about 30 seconds in oven or toaster oven.
Slice vanilla bean in half and scrape out seeds (reserve other half for another project -- vanilla beans keep best refrigerated.)
‘Smush’ vanilla seeds into the white sugar with pointer finger and thumb. Distribute evenly.
Into a non-reactive saucepan, pour milk and cream. Sprinkle vanilla sugar and half-scraped vanilla pod in and heat on low to medium until just boiled or hot. Whisk and shut off heat. Steep for at least 1 hour.
After an hour has passed, assemble what you will need to make appareil (custard base).
Make an ice water bath in a large bowl and set a smaller bowl fitted with a fine meshed sieve that will fit inside/on top of ice water bath.
Heat vanilla cream/milk mixture on low heat until mixture is HOT TO THE TOUCH. Do not boil or even simmer. Mixture is hot to the touch when you stick your finger in it and can’t keep it in there, but it will not burn you.
Separate eggs and save whites in fridge for another purpose (egg whites will keep, tightly covered, chilled, for at least 10 days). Whisk egg yolks until uniform & then whisk in demerara sugar. Whisk into this chilled butterscotch sauce.
Pour about one third of the hot liquid into sugar-yolk mixture and whisk well. Repeat until all hot dairy is whisked into yolks. Strain immediately into bowl through fine meshed sieve and chill until very cold. You may wash the vanilla pod and leave it to dry on top of your oven for a few days. When dry & brittle, grind in “spice/coffee” grinder with raw sugar to get the best vanilla sugar you have ever had the pleasure of meeting.
Season cooled custard gently with vanilla extract and salt until desired flavor. You may only need a few drops of vanilla extract and a few pinches of salt, depending on how aggressively you seasoned to taste your butterscotch sauce. do not eliminate this step. Butterscotch will not taste of itself without salt and vanilla.
When chilled, pour appareil into non-reactive tupperware (such as glass), tightly covered, and refrigerate overnight.
When you are ready to bake custards, choose ramekins or pudding dishes that are not deeper than they are wide. porcelain is preferred over glass.
Preheat oven to 275 degrees F.
Using a digital scale weigh custard into baking vessels at no more than 65 grams a piece. If you do not want to bake all your pot de crème mixture in one day, the base will keep for 10 days refrigerated, unless the cream or milk you used was about to expire.
Place filled custard ramekins in deep baking vessel taller than ramekins. Pour hot water from tap into baking vessel, having water no higher than the halfway point of ramekins.
Cover baking vessel with 3 layers of plastic wrap as follows: wrap 2 layers, taut, in one direction; then, carefully turn baking vessel around and repeat plastic wrap with one layer. You may also use aluminum foil if you are worried about your plastic wrap standing up to the heat.
Very carefully place this baking vessel in the middle of your preheated oven and set timer for 25 minutes.
When checking to see if your pot de crème are set, do not unhinge plastic wrap. Get very close to the baking vessel and while looking intently at custards’ middles, very gently move edge.
Pot de crème is set when middle looks like a still lake. Ramekins might jiggle a bit when tapped, but the whole surface will jiggle, not just the middle. It is over-baked if edges soufflé in any way.
As soon as pot de crème are set, take out and immediately remove plastic wrap. BE CAREFUL because escaping steam is hot enough to give you a nasty burn. I remove plastic with tip of butter knife and pull plastic away from my hand.
When ramekins are cool enough to handle, place on plate or baking tray and refrigerate until cool. If you prefer your silken custards warm, and not cold, you may leave custards out at room temperature for at least 6 hours and, between you and me, they are absolutely at their best never having seen the inside of a refrigerator.
But, if you must chill them make sure there are no savory aromas in your fridge—pot de crème is very sensitive and will pick up/adhere any off flavors of your fridge to themselves.
You may only wrap/cover pot de crème when the custard is cool, through and through.
Pot de crème are best eaten the day they are made, but they will last, refrigerated and covered, for about 4 days.
You may eat Butterscotch Pot de Crème unadorned or with salted nuts, a spot of cool cream, whipped cream, shortbread or fruits that would complement, such as pears or roasted apples.
For Shuna's Butterscotch, please find the recipe here: http://simplyrecipes.com/recipes/how_to_make_butterscotch/.