In a pot, gently heat up the cream, 200g castor sugar and vanilla - making sure it doesn't boil. In a separate bowl, combine the warm cream and cream cheese together and whisk until smooth - there should be no lumps. Pour the cream mixture into an espuma gun and chill until needed. In a pot, heat up 300g castor sugar until a golden caramel is formed. (TIP: do not stir, swirl the pot gently to ensure an even caramel forms without crystals). Add the puffed rice to the caramel, stir and pour onto baking paper. Spread evenly and allow that to set.
To serve, charge the espuma gun with two standard gas bulbs and shake vigorously. In a bowl or on a plate, pipe three medium-sized foam puffs onto the surface. Crush some of the puffed rice caramel over the top and drizzle with some passionfruit pulp. Serve immediately.