Cut vanilla bean(s) in half lengthwise with sharp knife and scrape out seeds.

Simmer 3 cups of milk and vanilla bean scrapings in a sauce pan over medium heat.

While milk is simmering, combine remaining 1 cup of milk, vanilla sugar & cornstarch in another bowl.

When milk has simmered, add in milk/sugar/cornstarch mixture and whisk over medium heat until sugar has dissolved & corn starch is well incorporated.

Removed from heat and pour into a bowl.

Cover mixture with plastic wrap, making sure the plastic wrap is touching the surface of the milk mixture to prevent a skin from forming.

Refrigerate mixture overnight. Pour into ice cream maker & churn until a thick consistency is reached.(See your instruction manual for additional instructions).