Preheat oven to 160 C (140 C fan forced). Grease 18 holes from two 12 hole (1½ tbsp or 30 ml) shallow round-based patty pans.
Place one biscuit each over top of 18 pan holes. Bake about 4 mins or until biscuits soften. Using the back of a teaspoon, gently press softened biscuits into pan holes, cool.
Stir condensed milk, butter and sugar in small heavy-based saucepan over heat until smooth. Bring to the boil, boil, stirring, about 10 mins or until mixture is thick and dark caramel in colour. Remove from heat, stir in juice.
Divide caramel mixture among biscuit cases. Refrigerate 30 mins or until set.