six 6-ounce ramekins; an air popper; a candy thermometer
Preheat the oven to 325 degrees F. Place six 6-ounce ramekins in a roasting pan and set aside.
In a saucepan over medium-high heat, mix 2/3 cup granulated sugar with 1/3 cup water. Bring to a boil, then cook until a medium-amber caramel forms, 7 to 10 minutes. Pour the caramel evenly among the ramekins.
Whisk together the eggs and egg yolks, remaining 1/2 cup granulated sugar and a pinch of salt in a bowl until pale and thickened.
Heat the whole milk, sweetened condensed milk, vanilla seeds and pods and cinnamon stick in a saucepan until simmering. Temper the hot liquid into the egg mixture by adding one ladle of the hot liquid into the eggs at a time while whisking constantly. Strain the mixture back into the pot, then whisk in the melted chocolate. Pour evenly into the ramekins. Place the roasting pan in the oven and pour hot water into the pan, allowing it to come halfway up the ramekins. Bake until just set, 20 to 25 minutes.
In the meantime, make the toffee popcorn. Pop the popcorn using an air popper and place it in a large mixing bowl. Mix in the peanuts.
To a saucepan, add the butter, brown sugar, corn syrup and a remaining pinch of salt. Bring to a boil, then cook to a temperature of 240 degrees F, not exceeding 260 degrees F. Remove from the heat and whisk in the baking soda and vanilla. Pour over the popcorn and peanuts and mix to combine, coating all of the popcorn. Pour out onto a silicone liner or piece of parchment and spread into an even layer, getting as much separation as you can. Sprinkle with the flaked sea salt. Allow to cool.