Combine milk, cream, corn syrup, sugar and salt in a large saucepan. Split vanilla bean and scrape out seeds; add to pan along with whole vanilla bean. Cook over medium heat until milk is steaming. Beat egg yolks until creamy. Remove vanilla bean from milk. Add about 1 cup of the hot mixture to the egg yolks and mix well. Add back to pan. Stirring frequently, cook until custard coats the back of a spoon or temperature is about 180°F. Do NOT boil. Remove from heat and add vanilla extract.
Transfer mixture to a bowl, cover and refrigerate for at least 8 hours or overnight.
Whisk the chilled custard and pour into ice cream maker or gelato machine. Make according to manufacturer’s suggestions. The gelato is ready when it is the consistency of soft serve ice cream or about 15 minutes. Serve immediately or pour into container and freeze until ready to serve.
Recipe Note – placing custard into a container with a spout makes it easier to pour into the machine.