I found this one on facebook: Favourite Recipes.
250g packet plain sweet biscuits
150g butter, melted
200g block milk chocolate, chopped
1/3 cup thickened cream
4 cups (360g) vanilla marshmallows (see note)
2 tablespoons milk
85g packet raspberry jelly crystals
Grease a 6cm-deep, 20cm square (base) cake pan. Line base and sides with baking paper, extending paper 3cm above edges of pan.
Using a food processor, process biscuits until fine crumbs. Add butter. Process until just combined. Press biscuit mixture evenly over base of prepared pan. Refrigerate for 10 minutes.
Meanwhile, place chocolate and cream in a heatproof, microwave-safe bowl. Microwave on HIGH (100%) for 40 seconds, stirring until smooth and combined. Pour over prepared slice base. Spread with a spatula to level. Refrigerate for 1 hour or until firm.
Place marshmallows and milk in a saucepan over medium-low heat. Cook, stirring, for 5 minutes or until marshmallows have melted and mixture is smooth. Pour over chocolate layer, spreading with a spatula to level. Refrigerate for 3 hours or until set.
Make jelly following packet directions. Refrigerate for 1 hour or until cold but not set. Pour over marshmallow layer (skim off any bubbles from top of jelly). Refrigerate for 4 hours or overnight until jelly is set. Cut into squares. Serve.