Beat eggs and simple syrup together and slowly add milk. Whisk ingredients until smooth. Pour contents into saucepan over low to medium heat and stir until thick. Remove from heat and allow to cool.

Strain mixture through sieve and stir in vanilla and bourbon. Cover and refrigerate.

Once cool, mix in cream and salt and whip until frothy.

Pour into glasses. Sprinkle with nutmeg and cinnamon. Serve chilled.