• 175 g (6 oz) digestive biscuits (graham crackers)
• 50 g (1¾ oz) unsalted butter, melted
• 18 passionfruit, plus extra to serve
• 3 sheets platinum-strength gelatine
• 600 ml (21 fl oz) sweetened condensed milk
• 300 ml (10½ fl oz) thick (double) cream (48% fat), lightly whipped

Fruit coulis

• 2 ripe mangoes
• juice of 1 lime
• 3 teaspoons caster (superfine) sugar

Grease and line a 20 cm (8 inch) square cake tin with baking paper, leaving the paper overhanging on two sides.

Put the biscuits in a food processor and finely crush. Add the melted butter and combine well. Press the biscuit mixture over the base of the tin and press down firmly. Refrigerate while you make the filling.

Cut the passionfruit in half, then scoop out the flesh into a sieve placed over a bowl. Press down on the seeds with the back of a spoon to extract as much juice as you can. You will need 170 ml (5½ fl oz/⅔ cup) of strained juice. Reserve 2 heaped tablespoons of seeds and discard the rest. Put the juice in a small saucepan over low heat and stir until hot.

Soak the gelatine sheets in cold water for 2-3 minutes until soft. Squeeze out the gelatine to remove the excess water, then add to the hot juice and stir until dissolved. Transfer to a large bowl, then add the condensed milk and stir until well combined. Fold in the softly whipped cream until just combined, then pour over the biscuit base in the tin and refrigerate for 3 hours or until set.

Meanwhile, to make the fruit coulis, peel and chop one mango into large pieces and put it in a food processor with the lime juice and sugar. Process until smooth and the sugar is dissolved. Cut the remaining mango into small pieces for serving.

To serve, cut the mousse cake into squares and top each piece with a little fruit coulis, a little mango and a small spoonful of passionfruit seeds.