Make the Custard: Place the chopped white chocolate in a large bowl and set a fine-mesh sieve over top of the bowl.
Combine the milk, sugar and salt in a medium saucepan and place over medium-low heat, stirring occasionally, until the sugar melts.
Meanwhile, whisk the egg yolks together in a medium bowl. Slowly pour the milk mixture into the egg yolks, whisking constantly, then scrape the mixture back into the saucepan and place over medium heat. Stir the mixture constantly with a rubber spatula until the custard thickens and coats the back of the spatula (it should be between 170 and 175 degrees F on an instant-read thermometer).
Pour the custard through the strainer and stir the mixture until the white chocolate is completely melted. Stir in the heavy cream, then stir in the vanilla extract to combine. Place the bowl in an ice bath and stir occasionally until the mixture is cool. Cover and chill in the refrigerator at least 8 hours, or overnight.
Make the Raspberry Swirl: An hour before you're ready to churn the ice cream, combine the raspberries, sugar and vodka in a small bowl and mash with a fork until juices are released but large chunks still remain. Cover and place in the refrigerator to chill until needed.
Churn the Ice Cream: Freeze the ice cream custard in an ice cream maker according to the manufacturer's instructions. As you remove the ice cream and place in a freezer-safe container, layer it with spoonfuls of the raspberry swirl mixture.
Notes
Notes:
You'll notice that there is vodka in the raspberry swirl; the alcohol keeps the swirl from freezing completely and becoming icy. You can omit it, but know that the texture of your raspberry swirl may be a bit compromised.