Salted Butter Caramel Ice Cream

Ingredients

• 1/2 cup sugar
• 3/4 teaspoon sea salt
• 2 cups whole milk, divided
• 1 cup heavy cream, warmed
• 1 1/4 cups sugar
• 4 tablespoons salted butter, cubed
• Scant 1/2 teaspoon sea salt
• 5 large egg yolks
• 3/4 teaspoon vanilla extract

Directions

1. Start the caramel praline by scattering the 1/2 cup (100g) sugar across the bottom of a medium, unlined, heavy duty saucepan in an even coating; a 6 quart/liter pan works well. Prepare a baking sheet with a silicone baking mat, or coat it very lightly with unflavored oil.
2. Set the pan over moderate heat and cook until the sugar begins melting around the sides. With a heatproof utensil, nudge the melted sugar from the bottom and edges into the middle, stirring gently until the sugar has dissolved. If a few lumps remain, don’t worry; they can melt as the caramel cooks. Keep cooking, stirring only now and then, until the caramel gives off a little smoke and smells like it is right on the edge of burning. This happens fast.
3. Right away, scatter the 3/4 teaspoon salt over the caramel without stirring. Pour the caramel onto the prepared baking sheet, then immediately pick up the sheet and tilt and swirl it, almost vertically, so the caramel spreads into the thinnest layer you can manage. Leave it to cool completely and harden.
4. For the ice cream, set up an ice bath: fill a large bowl about a third of the way with ice cubes, then add a cup or so of water so the ice floats. Place a smaller metal bowl, at least 2 quarts/liters, on top of the ice. Pour 1 cup (250ml) of the milk into that bowl, and set a mesh strainer over it.
5. Warm the cream in a small saucepan or microwave oven, then put it aside.
6. Scatter the 1 1/4 cup (250g) sugar evenly in a large saucepan with a capacity of at least 4qts/4l. Cook it over moderate heat until it caramelizes, using the same approach as for the praline.
7. When the sugar has caramelized, take the pan off the heat. Stir in the butter and salt until the butter has melted, then whisk in the warm cream gradually, about 1/4 cup at a time, stirring as you add it. The caramel may firm up and seize, but gentle stirring over low heat will help those pieces melt back in. Any stubborn bits can dissolve later or be caught in the strainer. Stir in the remaining 1 cup (250ml) of the milk.
8. In a small bowl, whisk the yolks. Slowly pour in some of the warm caramel mixture while stirring constantly, then scrape the warmed yolk mixture back into the saucepan. Cook the custard with a heatproof utensil, stirring the whole time and scraping across the bottom, until the mixture thickens. On an instant-read thermometer, it should register 160-170ºF (71-77ºC).
9. Strain the custard into the milk bowl set over the ice bath. Add the vanilla, then stir often until the mixture has cooled. Refrigerate for at least 8 hours, or until it is fully chilled.
10. Churn the chilled mixture in your ice cream maker as directed by the manufacturer.
11. As the ice cream churns, break the hardened caramel praline into tiny pieces, roughly the size of very large confetti, about 1/2-inch, 1 cm. A mortar and pestle works, or you can put the caramel shards in a sturdy freezer bag and crush them with a rolling pin. If you used a silicone baking mat, fold the mat over on itself several times to crumble the caramel.
12. When the caramel ice cream has finished churning, promptly stir in the crushed caramel, then transfer it to the freezer to firm up.