You need a 10-inch flan or cake pan.
Preheat oven to 325°F.
Make Caramel Syrup: Put the sugar in a small saucepan and stir in enough water to moisten all the sugar. Heat gently until the sugar is dissolved. Then bring to a rapid boil and cook for several minutes until caramel-colored. Do not stir. (Careful! Cooked sugar is very hot and can burn the skin if it spatters.) Immediately pour the hot caramel syrup into the flan pan and swirl the pan until it coats the bottom and a bit of the sides. The caramel will harden at this point and melt again later as the flan bakes.
To make custard: In a heavy medium saucepan, over medium heat, combine the white chocolate with the coconut milk, half and half, cinnamon, liqueur, orange zest and vanilla extract. Cook over medium heat just until mixture is scalding-hot (not boiling) and chocolate has melted, whisking often. Remove from heat; set aside for 20 minutes or until slightly cool.
Using a wire whisk, beat eggs and egg yolks, and sugar in a large bowl until blended. Continue whisking the egg mixture as you slowly ladle in the hot chocolate mixture, in a thin stream, until all the hot chocolate mixture has been used up.
Pour custard mixture into prepared flan pan and set into a slightly larger baking pan. Pour enough boiling-hot water into the larger baking pan to come halfway up the sides of your flan pan.
Bake flan for one hour. Remove, cool and refrigerate.
Run the tip of a small, sharp knife around the edge of flan to loosen from pan. Invert onto a serving plate with a lip before serving as the caramel syrup will have melted and created a delicious sauce.