In a medium saucepan, combine heavy cream, whole milk, brown sugar, and salt over medium heat, stirring until hot but not boiling, about 5-7 minutes.

In a separate bowl, whisk egg yolks until light and creamy, then temper with hot cream mixture.

Pour tempered yolk mixture back into saucepan and cook, stirring constantly, until custard thickens slightly and reaches 170°F, about 5-8 minutes.

Remove from heat, stir in vanilla extract, and cool mixture in an ice bath for about 10 minutes.

Toast pecans in melted salted butter in a skillet until fragrant, about 3-5 minutes; cool completely.

Churn the cooled base in an ice cream maker according to instructions, adding cooled pecans and browned butter during the last few minutes.

Transfer to an airtight container and freeze for at least 4 hours before serving.