Stir the condensed milk and melted butter in a medium bowl until mixed together well. In a separate large bowl, use a big wooden spoon to mix the crushed biscuits, lemon zest and coconut. Carefully pour in the butter and condensed milk, and stir well until everything is mixed together.
Line a 28x18cm tin with baking paper, and then use your hands to press the mixture into the tin. Transfer into the refrigerator to chill for 1 hour.
To make the passion fruit icing, use a wooden spoon to combine the icing sugar, passion fruit and butter in a medium bowl. Mix well until smooth and creamy. Pour the icing over the chilled slice and return to the fridge for 30 minutes.
While you wait for the slice to set, be sure to lick any icing that is left on the spoon! Once set, cut into squares.
Related slice recipes:
- Anzac slice
- Apple and sour cream slice
- Banana slice
- Caramel slice
- Cherry ripe slice
- Chocolate coconut slice
- Chocolate peppermint slice
- Coconut jam slice
- Too-easy lemon slice
- You can keep the slice in an airtight container in the fridge for up to four days.