Gently heat the heavy cream and whole milk in a saucepan over medium heat. Wait until small bubbles form around the edges—don’t let it boil. This should take 5–6 minutes.

In a separate bowl, whisk the egg yolks with granulated and brown sugar until light and creamy. Then slowly pour in half of the warm milk mixture while whisking constantly to prevent scrambling.

Pour the tempered egg mixture back into the saucepan. Stir continuously with a wooden spoon over low heat until it thickens and coats the back of the spoon (about 170°F).

Strain the thickened mixture through a fine mesh sieve into a clean bowl. Add vanilla and salt, press plastic wrap against the surface, and chill for at least 4 hours.

Melt the butter in a skillet and add chopped pecans. Toast over medium heat until golden and fragrant, about 3–4 minutes. Cool completely.

Pour the chilled custard into your ice cream maker and churn according to the manufacturer’s directions. This takes about 20–25 minutes.

In the final minutes of churning, add the cooled buttered pecans. Transfer to a freezer-safe container and freeze for at least 4 hours to set.