In a medium bowl, beat eggs and yolks. Beat in sugar until smooth. Set aside.
In a large saucepan over medium heat, combine cream, half-and-half, the vanilla bean and its scrapings, and the peel of one orange. Heat until bubbles form at edges of liquid, reduce heat to low and simmer 15 minutes. Beat hot cream into egg mixture, a little at a time, until all is incorporated. Stir in orange liqueur. Pour into 6 individual ramekins or custard cups.
Line a roasting pan with a damp kitchen towel. Place ramekins on towel, inside roasting pan, and place roasting pan on oven rack. Fill roasting pan with boiling water to reach halfway up the sides of the ramekins.
Bake in preheated oven 45 to 60 minutes, until set. Let cool completely before serving.