Warm the milk, sugar, salt and 1/2 cup of the cream in a medium saucepan. With a sharp paring knife, scrape the flavorful seeds from the vanilla bean and add them, along with the pod, to the hot milk mixture, Cover, remove from the heat, and let steep at room temperature for 30 minutes.
Rewarm the vanilla-infused mixture. Pour the remaining 1 cup cream into a large bowl and set a mesh strainer on top. In a separate medium bowl, whisk together the egg yolks. Slowly pour the warm mixture into the egg yolk, whisking constantly, then scrape the warmed egg yolks back into the saucepan.
Stir the mixture constantly over medium hear with a heatproof spatula, scrapping the bottom as you stir, until the mixture thickens and coats the spatula. Pour the custard through the strainer and stir it into the cream to cool. Remove the vanilla bean, wipe it clean of any egg bits, and add it back to the custard. Stir in the vanilla and stir until cool over an ice bath. Chill thoroughly in the refrigerator.
When ready to churn the ice cream, remove the vanilla bean (it can be rinsed and reused). Freeze the ice cream in your ice cream maker according to the manufacturer’s instructions. While the ice cream is freezing, chop the peanuts into bite-sized pieces.
Fold the peanut pieces into the frozen ice cream as you remove it from the machine, and layer it with Fudge Ripple.