Turn on the heat to medium-high in a fry small skillet toast pecans for 3-5 minutes, constantly stirring until pecans are fragrant. Remove from heat, add 1 tablespoon of butter and dark brown sugar, stir to combine and cool.
In a stand mixer or a bowl with a hand mixer, whip heavy cream and kosher salt until stiff peaks form, about 1 ½ minutes. Fold in condensed milk, make sure you keep some streaks of cream and be careful not to take all the air out of the stiff peaks.
In a small bowl, combine cooled melted butter and vanilla. Fold butter mix and pecans into the ice cream base. Pecans should be evenly distributed and covered in an ice cream base.
Transfer to dish and cover and pop in the freezer overnight before enjoying. Set ice cream out for 2 minutes before serving