In a medium saucepan, combine heavy cream and whole milk over medium heat. Stir gently and wait for small bubbles to form around the edges, about 5–6 minutes, making sure it doesn’t reach a boil.

While the cream heats, whisk together egg yolks with granulated and brown sugar until pale and creamy.

Slowly pour half of the warm cream mixture into the egg yolk mixture while whisking continuously.

Return the saucepan to low heat and cook the combined mixture, stirring constantly with a wooden spoon until it thickens and coats the back of the spoon.

Remove from heat, strain through a fine mesh strainer into a bowl, add vanilla extract and a pinch of salt, then chill in the refrigerator for at least 4 hours.

In a skillet over medium heat, melt unsalted butter, then add chopped pecans and toast them for about 3–4 minutes.

Once the custard mixture is chilled, pour it into the ice cream maker and churn according to manufacturer's instructions, adding toasted pecans towards the end.

Transfer to a freezer-safe container, cover tightly, and freeze for at least 4 hours.