In a medium saucepan over medium heat, warm 1 cup of heavy cream, milk, sugar, corn syrup, and salt. Scrape the seeds from the vanilla bean and add both the seeds and the bean to the warm milk mixture. Cover, remove from the heat, and let steep at room temperature for for 30 minutes.

Pour the remaining 1 cup of cream into a large bowl and set a fine mesh strainer over the bowl. In a separate medium bowl, whisk together the egg yolks. Slowly pour the warm milk mixture into the egg yolks, whisking constantly to temper the yolks, then scrape the tempered yolks back into the saucepan.

Stir the mixture constantly over medium heat with a heatproof spatula, scraping the bottom of the pan as you stir until the mixture thickens and coats the spatula. Pour the custard through the fine-mesh strainer and stir in the cream. Return the vanilla bean to the custard, add the vanilla extract and vodka, and stir until cool over an ice bath.

Chill the custard thoroughly, preferably overnight, in the refrigerator. When ready to churn, remove the vanilla bean and freeze the mixture in an ice cream maker according to the manufacturer's instructions. Transfer to a freezer-safe container and freeze until firm. Enjoy!