Step 1

Heat milk to boiling point in a saucepan. Cover pan and remove from heat. Whisk egg yolks and honey together in a bowl until thickened. Stir in vanilla and cinnamon. Slowly pour hot milk into the egg yolk mixture, whisking constantly. Return the mixture to a saucepan and cook over a low heat, stirring with a wooden spoon, until thickened slightly (coating the back of the spoon). Do not allow to boil.

Step 2

Allow custard to cool to room temperature. Loosely cover the mixture with plastic wrap and refrigerate until cold (a minimum of 3 hours).

Step 3

Freeze in an ice cream maker until just beginning to set. Stir in sour cream and freeze in the ice cream maker until set.