Peel and seed a ripe Cherimoya. Separate pulp and chop very fine.
Split vanilla bean down the center and scrape out seeds.
Combine cream, vanilla bean seeds and salt in a saucepan over medium heat. Simmer for 15 minutes. Remove mixture from heat, add orange zest and cherimoya pulp, set aside. In a mixing bowl, place the egg yolks and sugar. Whisk by hand until just combined, then slowly pour in the warm cream mixture and mix thoroughly.
Place 4 ramekins in a large baking dish. Pour mixture into ramekins and fill almost to top. Bake in a water bath (so water is about 2/3 up the side of ramekins) for about 45 minutes to 1 hour or until set. Remove creme brulee from water bath and allow to cool 30 minutes.
Refrigerate 6 hours or overnight.
Sprinkle 1 tablespoon of sugar over top of each custard. Place under broiler until sugar caramelizes (turns a light golden brown).