Place heavy cream, half and half, and cinnamon stick in a saucepan over medium heat. Bring to a simmer (about 175°F). Remove from heat, cover, and let steep 30 minutes. Remove cinnamon stick.

Add half of the sugar to the cream mixture and bring back to a simmer (about 160°F), stirring to dissolve sugar. Remove from heat.

In a medium bowl, whisk together egg yolks and remaining sugar until thick. While whisking, slowly add cream to the egg mixture. Return to saucepan.

Bring custard back to a low simmer (165-167°F), stirring continuously. Remove from heat and immediately strain into a clean bowl. Cover and refrigerate overnight.

Set up an ice cream machine and churn according to the manufacturer's directions.

Pack ice cream in an airtight container and store in a freezer.