In a medium sauce pan heat your half and half and sugar over a medium low heat until it is simmering. Then remove from heat.
In a bowl whisk your eggs. Then Temper them. To do so slowly pour about half of your half and half mixture into your egg mixture, while whisking vigorously. Then slowly add your egg mixture back to your sauce pan with the remaining half and half mixture. While doing this whisk vigorously.
Add your heavy cream, seeds from your vanilla bean, and cinnamon to your pan.
Place pan back on the stove and heat over medium low heat while whisking continuously. Do so until your mixture as thickened enough that it coast the back of your spoon. About 30 minutes.
Then take off stove and cool to room temperature for about an hour. Then place mixture into fridge for about 4 hours or overnight.
Pour mixture into ice cream mixer and churn until mixture has doubled in volume and it is thick fluffy and creamy looking. About 30 minutes.
Once done pour in loaf pan and place back in freezer for about 2 hours or more if desired.