Combine the heavy cream, sugar, and butter in a medium saucepan over medium heat.

Stir continuously until the sugar dissolves and the mixture starts to bubble.

Continue cooking for 8–10 minutes, stirring occasionally, until the caramel turns golden brown and thickens.

Stir in the vanilla extract and sea salt.

Let the caramel cool slightly before serving—it will thicken more as it cools.