Step 1

In a large Pyrex measuring cup or heatproof bowl, whisk the yolks with ¼ cup of the brown sugar. Set aside.

Step 2

In a heavy saucepan, stir together the cream, milk, salt, and the remaining ¼ cup of brown sugar and put the pan over medium-high heat. When the mixture starts to simmer, decrease the heat.

Step 3

Remove about ½ cup of the hot cream mixture while constantly whisking the eggs, slowly drizzle the cream into the egg yolks. Repeat with another ½ cup of hot cream, then pour the egg-cream mixture back into the saucepan, whisking as you pour.

Step 4

Cook the mixture carefully over medium heat, stirring constantly, until it is thickened, about 1-2 more minutes.

Step 5

Strain the custard mixture through a fine-mesh strainer into a clean container. Set the container into an ice-water bath (I fill my sink with ice cubes, then adds some water). Stir occasionally, till cool.

Step 6

Remove the container from the ice-water bath, cover with plastic wrap, and refrigerate for at least 2 hours or overnight.

Step 7

While the ice cream base cools, make the caramel.

Step 8

Set the warm cream by the stove so it's at hand when you need it. Put 2 tablespoons of the sugar in a heavy saucepan over medium-high heat. When the sugar is melted around the edges and starts to turn golden, stir the mixture gently and add another 2 tablespoons of sugar to the pan.

Step 9

Continue to add the remaining sugar 2 tablespoons at a time, stirring frequently and allowing most of the sugar to melt before you add more. Watch carefully as the sugar darkens, stirring gently to help it melt evenly.

Step 10

When all the sugar has caramelized, slowly add the cream. It will bubble furiously.

Step 11

When the bubbling slows down, gently stir in the cream to blend. If you have any hard sugar lumps, just keep the burner on low and cook till sugar melts. Stir in salt and vanilla and allow to cool to room temperature.

Step 12

Freeze the ice cream as directed by your ice cream maker.

Step 13

When the ice cream is frozen, layer about a third of it into your container. Drizzle 2 tablespoons of caramel on top of ice cream, then repeat again two more times. You will have leftover caramel.

Step 14

Use a knife or a chopstick to swirl the caramel. If you prefer softer ice cream, eat right away or else freeze for about 4 hours before serving.