In a large bowl, whisk the sweetened condensed milk, vanilla, vanilla bean seeds, salt, and bourbon, if using, until completely combined.

In the bowl of a stand mixer fitted with a whisk, beat the cream cheese on medium until smooth. Turn the mixer to low and add the heavy cream in a slow steady stream, mixing until combined. Increase the speed to medium-high and whisk until stiff peaks from, 3 to 4 minutes.

Add half the whipped cream mixture to the sweetened condensed milk mixture and whisk until completely combined. Using a rubber spatula, gently fold in the remaining whipped cream mixture until no streaks remain. pour into a 9 in [23 cm] loaf pan or Pullman pan with a lid and freeze until firm, 6 hours or, covered, up to 1 week.