Place your large mixing bowl and whisk attachment (if using a stand mixer) or beaters (if using a hand mixer) in the freezer for 10-15 minutes. This helps the cream whip up faster and more stable.

Pour the cold heavy cream into the chilled bowl. Using your stand mixer on high speed or a hand mixer, beat the cream until stiff peaks form. This might take 3-5 minutes, depending on your mixer. The cream should hold its shape when you lift the whisk.

In a separate medium bowl, gently whisk together the chilled sweetened condensed milk, pure vanilla extract, and fine sea salt until well combined.

Carefully add about one-third of the whipped cream to the condensed milk mixture. Gently fold it in with a rubber spatula until just combined. This lightens the condensed milk mixture, making it easier to incorporate the rest.

Add the remaining whipped cream to the mixture. Gently fold until no streaks of condensed milk remain and the mixture is uniform. Be careful not to deflate the whipped cream; the air is what makes it light and creamy.

Pour the ice cream base into a 9x5-inch loaf pan or a 1.5-quart freezer-safe container. Cover it tightly with plastic wrap or a lid. Freeze for at least 6 hours, or preferably overnight, until firm.

When ready to serve, let the ice cream sit at room temperature for 5-10 minutes to soften slightly, then scoop and enjoy!