Toast the pecans: In a skillet over medium heat, melt butter. Add chopped pecans, brown sugar (if using), and a pinch of salt. Toast, stirring often, for about 4–5 minutes until fragrant and lightly golden. Remove from heat and let cool.

Make the custard base: In a saucepan, combine heavy cream, milk, and half the sugar. Heat over medium until steaming but not boiling.

Whisk egg yolks: In a bowl, whisk egg yolks with the remaining sugar until thick and pale. Slowly whisk in a small amount of the hot cream mixture to temper, then pour the yolk mixture back into the saucepan.

Cook the custard: Stir constantly over low heat until the custard thickens and coats the back of a spoon (170–175°F). Do not boil. Remove from heat, stir in vanilla and a pinch of salt.

Strain and chill: Pour custard through a fine mesh sieve into a clean bowl. Cover and refrigerate for at least 4 hours, preferably overnight.

Churn: Once chilled, churn in your ice cream maker according to the manufacturer’s instructions (typically 20–25 minutes). In the last few minutes of churning, fold in the toasted pecans.

Freeze: Transfer to a freezer-safe container and freeze for 2–4 hours until fi