In a heavy saucepan, heat heavy whipping cream with orange zest until almost boiling (you should see small bubbles starting to come up to the surface of the mixture).
Pour cream mixture through a fine mesh sieve to remove orange zest.
Pour ¼ of the hot cream mixture into the egg yolks while stirring (you want to make sure not to cook the eggs).
Add vanilla and orange liquor until incorporated.
Stir in remaining cream mixture and stir until well incorporated.
Fill 4-5 oz ramekins until almost full.
Set ramekins into a pan of boiling water, place in the pre-heated over, and bake for 30 minutes (or until center is set but still loose).
Remove ramekins from pan and refrigerate for at lest 3 hours or over night.
Topping
Top each serving with 1-tablespoon sugar and heat under the oven broiler or with a culinary torch.
Wait for melted sugar to harden before serving.
Garnish with orange slices or other fruit if desired.
