Step 1

Line base and sides of a 26 x 16cm (base measurement) slice pan with baking paper, extending paper at long sides for handles. Place half the biscuits over base of prepared pan in a single layer, shiny-side up. Cut to fit tightly. Set aside.

Step 2

Using an electric mixer, beat milk, cream and pudding mixture in a large bowl until thick, smooth and creamy (don't overmix; mixture will become lumpy). Carefully spread mixture over biscuit base in prepared pan; level top. Top with remaining biscuits, shiny-side up, cutting to fit tightly. Gently press biscuits down.

Step 3

Combine sifted icing sugar and passion fruit in a small bowl until smooth. Spread icing over top of slice. Chill for 1 hour or until firm. Transfer to a chopping board, then cut into squares. Serve.