Preheat oven to 400°F
Wrap the potatoes in aluminum foil. Once the oven has preheated, bake the potatoes for 50 minutes to an hour or until extremely tender. Set aside and let cool. This can be done the day before.
Lower oven to 325°F.
In a saucepan, heat the cream over medium heat until it’s hot but not boiling. Turn off the heat and stir in vanilla.
In a bowl, whisk together egg yolks, sugar, and salt until smooth.
Slowly pour in the warm cream while whisking (this keeps the eggs from scrambling).
Pour the mixture into a small oven-friendly tart or pie dish.
Place the tart or pie dish into a baking dish, then pour hot water around the tart or pie dish until it comes halfway up the sides.
Bake for 35–40 minutes, until the centers are just set (slightly jiggly).
Cool, then refrigerate at least 2 hours (or overnight).
Peel off the top layer of the potatoes and gently press down into the flesh to create a well.
Fill the well with the cooled custard and sprinkle a thin layer of sugar on top.
Broil the potatoes on the top rack of your oven for 1-2 minutes or until the sugar is golden brown. If you have a pizza oven, preheat it to high, place the potato onto a pizza peel, and hold it up close to the flames until the sugar is golden brown.
Let them cool for a minute and break in!
