Place the yolks, sugar, milk, flour, and salt in a large bowl and whisk until smooth. Whisk in the lime zest, juice, and passionfruit pulp.
Whip the egg whites in a separate bowl until they hold stiff peaks. Add about â…“ of the passion fruit mixture to the whipped egg whites, and fold together until just combined. Fold in the remaining passion fruit mixture, and transfer the batter into five 4-oz ramekins.
To make a water bath, place the ramekins in a larger baking dish and pour hot water all around, until it comes about halfway up the sides of the ramekins. Bake until the cake has risen and is springy to the touch, about 23-33 minutes. Garnish with additional passionfruit to serve.