TO MAKE THE ICE CREAM BASE:
In a medium bowl, whisk egg yolks, granulated sugar, and salt together; set side.
In a 4-quart heavy-bottomed non-stick pan over medium heat- combine the milk and whole vanilla bean that has been split open and the seeds scraped out (both the bean pod and the seeds go into the pan with the milk - if you're using vanilla extract instead, don't add it at this point). Over medium heat, cook the milk until it starts to bubble around the edges of the pan. Remove from heat and whisk about 1/4 cup of the hot milk into the egg yolk mixture; repeat with another 1/4 cup of hot milk. Pour the now warm egg yolk mixture into the pan containing the remaining hot milk; stir to combine. Return pan to the stove top (med heat) and cook- stirring constantly, until the mixture reaches a temperature of 170-180F.
Remove pan from heat and strain mixture through a sieve into a large bowl to remove the vanilla bean pod and any bits of egg that might have coagulated. Stir in cold heavy cream (and vanilla extract, if using). Chill the ice cream base in an airtight container in the fridge for at least 4 hours before churning (or up to 48 hours - the colder, the better).
TO CHURN THE ICE CREAM:
Process the ice cream base according to the manufacturer's instructions that were included with your ice cream maker.
Divvy the ice cream into heat-safe ramekins- leaving about 1/4-inch of space at the top. Put the ramekins into the freezer for several hours until the ice cream is hard. This can be done several days in advance - just cover ramekins with plastic wrap.
Just before serving, use kitchen torch to heat the surface of the ice cream just slightly so the turbinado sugar will stick to it. Add a layer of turbinado sugar over the top of each ramekin; then caramelize the sugar using a kitchen torch. I like an extra thick layer of caramelized sugar so I repeat this step by sprinkling a second layer of turbinado; then caramelize with the torch again. Serve immediately.