Chill a 9" x 5" metal loaf pan in the freezer for at least 30 minutes.

In a mixing bowl, whisk together sweetened condensed milk, brown sugar, vanilla extract, and salt until smooth.

Whip heavy cream in a separate bowl until firm peaks form, 3-5 minutes.

Gently fold half of the whipped cream into the condensed milk mixture, then fold in the remaining whipped cream.

Transfer the mixture to the chilled loaf pan and cover tightly, then freeze for at least 2 hours.

Preheat oven to 350°F (175°C). Melt butter in a skillet, toast pecans for 12-15 minutes, then cool.

After 2 hours, stir in cooled, toasted pecans to the ice cream mixture and cover again.

Return to freezer for additional 3 hours or until firm. Let sit at room temperature for 5-10 minutes before serving.