Place the sugar in a seal-able container. Push the vanilla beans into the sugar and close container. Let stand several days to a week so that the sugar takes on the flavor of the vanilla. Remove beans.

Slice one vanilla bean length-wise and scrape out the seeds into a large saucepan. Place the halves of the bean in the saucepan and cover with half-and-half. Heat on medium until steaming hot (180°F), then remove from heat. Remove vanilla bean pod.

In a large bowl, whisk together egg yolks and sugar. While whisking, slowly add hot half-and-half to the egg yolks, then return to the saucepan.

Cook custard over medium heat, whisking continuously, until thickened (175°F). Remove from heat.

Pour custard into a large bowl, and whisk in heavy cream and vanilla extract.

Chill a minimum of 8 hours, then churn, following the directions for your ice cream freezer.