In a small saucepan, over medium-low heat, stir together the heavy cream, milk, brown sugar, vanilla extract and salt. Heat the mixture over medium-low heat until the sugar has dissolved and the mixture is hot, but not bubbling. Don’t let it boil. As soon as you see small bubbles around the perimeter of the saucepan, the milk is warm enough and ready.

In a medium bowl, whisk the egg yolks until they lighten in color, about 2 minutes. While stirring, slowly add a cup of the hot cream mixture into the yolks making sure you keep whisking vigorously to prevent the yolks from curdling.

Next, stir in the yolk mixture into the saucepan. Cook over medium-low heat, stirring often, until the mixture reaches 170º F when checked with a candy thermometer or when the mixture is thick enough to coat the back of a spoon, about 10 minutes.

Pour custard through a fine mesh strainer into an airtight container and cool in an ice bath, then cover and refrigerate for about 3-4 hours or overnight.

In a light-colored skillet over medium heat, melt the butter. Once melted, the butter will begin to foam and sizzle around the edges. Swirl the pan so the butter browns evenly. When the butter is golden brown (like honey), about 4 minutes, stir in the pecans. Cook stirring often until the pecans are toasted and the mixture becomes aromatic, about 1-2 minutes. Remove from the heat and transfer the buttered pecans and any bits of brown butter to a baking sheet lined with parchment paper or to a plate to cool.

Once the nuts are mixed in, transfer to a freezer-safe container and freeze for about 4 hours before serving.