Halve the passion fruit and scoop out the pulp into a saucepan. Add the orange juice and boil until reduced by half. Strain into a jug, to give about 250ml, rubbing through with a spoon. Discard the pips. Cool.
Heat oven to 180C/fan 160C/gas 6. Butter the sides and base of 8 x 150ml ramekin dishes evenly, then coat with 1 tbsp of sugar.
In a large bowl, whisk together half of the caster sugar, the orange zest, ricotta, fromage frais, 1 tbsp cornflour and the egg yolks. Fold in the mango flesh and 6 tbsp of the reduced juice.
Whisk the egg whites until soft peaks form, then whisk in the remaining sugar. Fold this into the ricotta mix and spoon into the prepared dishes, levelling the top. Set the dishes in a large, deep roasting tin and pour round boiling water to come halfway up the dishes. Cover the whole roasting tin with foil and seal the edges loosely. Bake for 50 mins until the soufflés have risen and set.
Meanwhile, make the sauce. Blend the 1 tsp cornflour with a little cold water. Bring the remaining juice to the boil in a small saucepan, mix some into the cornflour, then pour back into the pan with the Curaçao or Cointreau. Heat, stirring until thickened. Set aside to cool. Dust each dessert lightly with icing sugar and drizzle with a little sauce. Serve remaining sauce separately.