1/2cup4 ounces/113 grams firmly packed light or dark muscovado sugar
1/2teaspoonfine sea salt
2 1/4cups19 1/2 ounces/540 grams half and half*
3/4teaspoonvanilla bean paste or pure vanilla extract
Whipped Creamfor serving
Flaky sea saltfor serving
Buttermilk Caramel Sauce:
1cup7 ounces/200 grams turbinado sugar or grated piloncillo
2tablespoons1 ounces/28 grams water
1tablespoonhoneybrown rice syrup or agave nectar
1/4teaspoonsfine sea salt
4tablespoons2 ounces/57 grams unsalted butter, cut into cubes
1/24 1/2 ounces/120 grams well-shaken buttermilk
1/2cup4 1/2 ounces/120 grams heavy cream
1/4teaspoonpure vanilla extract
To make the Pot de Creme: Position a rack in the center of the oven and preheat the oven to 325 degrees F. Set 8 small (6 to 8-ounce) ramekins, cups, or coffee cups in a small roasting pan. (Just an FYI, I used these Staub Pots and they took a bit longer to cook.) Bring a kettle of water to a boil.
In a medium bowl, whisk the egg yolks until smooth.
In a medium saucepan over medium heat, melt together the butter, sugar, and salt. Whisking often, cooking until the sugar begins to caramelize, darkening in color and smelling nutty, 3 to 4 minutes. Carefully and slowly whisk the half-and-half. The caramel will seize at first, melting back into the mixture once all the liquid is added. Stirring often, bring the mixture to a simmer. Remove the pan from the heat. Stir in the vanilla bean paste or vanilla extract.
Whisk a small amount of the hot liquid into the yolks to warm them and then gradually whisk in the remainder. Set a fine mesh sieve over a large heatproof measuring cup. Pour the custard through the sieve. Divide the custard evenly among the ramekins.
Slice out the oven rack and place the roasting pan on the rack. Carefully fill the roasting pan with boiling water halfway up the ramekins, taking care not to splash any water into the custards. Slide the rack back into place. Bake until the custards are just set but still jiggle when tapped and a thin knife inserted into the center of one of the custards comes out clean, 30 to 45 minutes, depending on the size, depth, and thickness of the ramekins (use the "jiggle test" and knife tester as your clues for doneness). Let the custards cool out of the roasting pan for 5 minutes. Cover loosely with plastic wrap and chill for 3 to 4 hours.
To make the Buttermilk caramel: In a medium heavy-bottomed saucepan, gently stir together the sugar, water, honey, and salt. Set the pan over medium-high heat. Stirring gently, bring the mixture to a boil, and then stop stirring. Cook the sugar syrup until it caramelizes, about 5 to 7 minutes, swirling the pan occasionally. The color of the sugar will make it a bit tough to gauge by sight if the sugar is caramelizing, so watch for a thickening of the syrup and a few wisps of smoke coming from the pot, and keep your nose turned in for a slightly smoky smell; if you'd like to use a candy thermometer for extra insurance, caramelization will happen at about 300 degrees F.
Remove the caramel from the heat and whisk in the butter. Carefully whisk in the buttermilk and cream. Place the pan back on the heat and bring the caramel back up to a simmer, whisking all the while. Cook for 1 additional minute; if any lumps formed when you poured in the liquids, they should smooth out completely during this time. Remove the pan from the heat again and whisk in the vanilla extract. Chill in the refrigerator until you're ready to serve.
To serve, top each pot de creme with a dollop of whipped cream, a drizzle of caramel sauce and a sprinkling of sea salt.
*I made my half and half since I didn't have it in the fridge. I added one part heavy cream and one part whole milk.