Put the dairy-free milk, the dairy-free cream, sugar, zest, vanilla pod and seeds in a heavy-based pan and bring just to the boil. Stir to dissolve the sugar. Take off the heat.
Meanwhile place the gelatine in a small bowl of water and leave for 5 minutes to soften. Squeeze any excess water out of the gelatine and whisk into the warm milk mixture. Cool to room temperature, then strain into a jug and divide between 4 dariole moulds. Cover and chill for a minimum of 5 hours or overnight.
In a small saucepan cook the extra 2 tablespoons of sugar and the seeds and juice from the passionfruit for 2 minutes until syrupy. Remove from the heat and allow to cool.
Dip the dariole moulds into a bowl of hot water for 30 seconds to loosen before turning out and spoon over the cooled passion fruit sauce.