Salted Butterscotch Pots de Crème

Ingredients

For the Salted Butterscotch Pots de Crème:

4 tablespoons unsalted butter

1 cup light brown sugar

3 cups heavy cream

1 cup whole milk

1 1/2 teaspoons pure vanilla extract

1/2 teaspoon salt

6 egg yolks

maldon salt, for serving

For the Hazelnut-Espresso Lace Cookies: 

1 tablespoon unsalted butter

1 tablespoon + 1 teaspoon light brown sugar

1/2 tablespoon light corn syrup

a heaping 1/4 teaspoon espresso powder

1 tablespoon + 1 teaspoon all-purpose flour

2 1/2 tablespoons ground, roasted hazelnuts (or hazelnut meal)

1/4 teaspoon vanilla

Instructions

1. To prepare the pots de crème: Preheat the oven to 325F. Line the bottom of a roasting pan or baking dish with paper towels, set on a baking sheet for stability and set aside. Put several cups of water on the stove over medium-low heat to slowly come to a boil -- we'll use this for our water bath later.
2. In a medium, heavy-bottomed sauce pan combine the butter and brown sugar over medium heat and stir occasionally with a wooden spoon or heatproof spatula. The butter and sugar may separate at first, but as the sugar dissolves they will come together. Cook and stir until the sugar is completely dissolved and the mixture begins to bubble and brown (it may also smoke a little, this is fine), about 15-20 minutes.
3. Lower the heat and slowly add the cream, 1 cup at a time. The sugar will sputter and seize up when you add the first cup, so that it will look like you have little pieces of butterscotch candy floating in your cream. Continue to cook and stir until all of the seized butterscotch has melted back into the cream mixture then add all of the remaining cream and the whole milk.
4. Add in the vanilla extract and salt and stir until the salt has dissolved. Remove from the heat and set aside -- this is your butterscotch mixture.
5. In a separate, heatproof bowl whisk together six egg yolks until slightly pale, about 1 minute. Temper the eggs by adding about 1/2 cup of warm butterscotch mixture to the egg yolks while constantly whisking. Once the yolks have been warmed to the touch, pour the mixture entire mixture into the pot of butterscotch and whisk to combine.
6. Strain the mixture into a large measuring cup or bowl then divide between 10 to 12 ~4 oz. ramekins or mini mason jars. Leave a little bit of room at the top for whipped cream. You should be able to fill between 10 to 12 containers depending on the size of your containers and the amount your pour into each. Place the ramekins into the lined baking dish the carefully pour in the boiling water so that it comes up half way each ramekin. Cover tightly with foil and poke two holes at either end.
7. Bake for between 25-50 minutes -- the baking time will depend largely on the temperature of the custard when you put it into the oven. Check for doneness around 25 minutes by tapping the side of each ramekin. If the mixture ripples like water then put them back in to continue baking. If the mixture jiggles like set Jell-O then they're done. Be cautious not to overbake or they will become grainy. Mine took closer to 50 minutes because I moved slowly and let the mixture cool quite a bit before baking.
8. As soon as the custards reach Jell-O texture, remove them from the oven, take off the foil cover and place on a cooling rack to cool in the water bath. Once the pots de creme have reach room temperature, remove them from the water bath and chill in the refrigerator for at least 3 hours, up to two days, before serving.
9. To prepare the lace cookies: Preheat the oven to 350F and line two baking sheets with parchment paper.
10. In a small saucepan, heat the butter, sugar, instant espresso and corn syrup over low heat, stirring often, until the butter melts and the sugar dissolves. Increase the heat to medium-high and stir constantly, until the mixture comes just to a boil.
11. Remove the pot from the heat and stir in the flour and salt until incorporated. Stir in the hazelnut meal and the vanilla. Let the mixture cool for a few minutes, until it firms up a little bit and becomes easier to pinch into a dough. 
12. Use a 1/4 teaspoon to scoop out small rounds of the dough, and roll into tiny balls. Place 3 inches apart on the lined baking sheets. Bake one sheet at a time for 7-8 minutes each. Remove from the oven and let set on the baking sheets for about 5 minutes, then transfer to a rack to finish cooling. Note: Lace cookies will stay fresh and cripsy for about a day. You can make them ahead of time and re-crisp before serving by placing in a 325F oven for 5 minutes. 
13. To serve: Garnish each custard with a dollop of whipped cream, half a lace cookie and a sprinkle of maldon salt. Serve alongside more lace cookies for dipping.