For orange caramel, simmer orange juice in a saucepan over medium-high heat until reduced by half (3-4 minutes), add sugar and stir until dissolved, brushing down sides of pan with a wet pastry brush to remove sugar crystals. Bring to the boil and cook without stirring until dark caramel (2-3 minutes). Pour into an 18cm-diameter cake tin, quickly swirl tin so caramel coats base and sides, and stand until set.
Preheat oven to 160C. Bring milk, cream, orange rind and orange juice to the simmer in a saucepan over medium heat, remove from heat, add Cointreau and stand to infuse (20 minutes).
Whisk eggs, yolks, sugar and cardamom in a bowl, add milk mixture, whisk to combine, strain into a jug, then pour into caramel-lined tin. Place tin in a roasting pan lined with a tea towel, pour in enough boiling water to come halfway up sides of tin, cover with foil and bake until custard is set but has a slight wobble in the centre (50 minutes-1 hour). Remove from water bath, cool to room temperature, then refrigerate until completely chilled (4 hours).
Run a knife around sides of tin and place a serving plate on top. Invert tin and plate, remove tin and serve.
This recipe is from the July 2012 issue of Australian Gourmet Traveller.