Step 1

Grease a 3cm-deep, 18cm x 28cm (base) slice pan. Line base and sides with baking paper, extending paper 5cm above edges on all sides. Place biscuits in a food processor. Process until fine crumbs form. Add butter. Process until just combined. Press biscuit mixture into base of prepared pan. Refrigerate for 30 minutes or until firm.

Step 2

Stir condensed milk and lemon juice in a bowl until combined. Place 3/4 cup boiling water in a small jug. Sprinkle over gelatine. Stir until dissolved. Stir gelatine mixture into condensed milk mixture. Pour over biscuit base. Refrigerate for 1 hour or until set.

Step 3

Meanwhile, place jelly crystals in a large heatproof bowl. Add remaining boiling water. Stir until dissolved. Add 200ml cold water. Stir to combine. Stir in passionfruit pulp. Stand for 10 to 15 minutes to cool to room temperature.

Step 4

Pour jelly mixture over slice. Refrigerate for 2 hours or until set. Carefully remove slice from pan. Sprinkle with mint leaves. Cut into pieces. Serve.