Heat oven to 325F and press the crust into a springform pan.

Beat cream cheese and sugar until smooth, then add eggs one at a time.

Mix in the orange liqueur, zest, and sour cream until silky.

Pour over the crust and bake 60-65 minutes until just set.

Cool slowly in the oven with the door ajar to avoid cracks.

Chill at least 6 hours, then garnish with extra zest before serving.