Step 1

Line an 18cm x 27cm slice tin with baking paper.

Step 2

In a food processor, blitz biscuits into a fine crumb. Add melted butter and 1/3 cup condensed milk, and pulse to combine. Press into an even layer in prepared slice tin.

Step 3

Melt chocolate with remaining condensed milk in a small bowl over a saucepan of simmering water. Alternatively, melt in 30-second bursts in the microwave. Stir well to combine, then pour over the biscuit base in a slice tin and spread out into an even layer. Refrigerate for 1 hour until set. Slice into squares and serve.