Step 1

Preheat oven to 180°C. Brush a 16 x 26cm (base measurement) non-stick slice pan with melted butter to lightly grease. Line the base and 2 opposite sides with non-stick baking paper, allowing it to overhang.

Step 2

Combine the chocolate and butter in a medium saucepan over low heat and stir with a metal spoon for 5 minutes or until chocolate melts. Add the sugar and cook, stirring, for 5 minutes or until sugar dissolves.

Step 3

Remove from heat and set aside for 5 minutes to cool. Stir in the egg and flour until combined. Stir in the marshmallows and peanuts until combined. Spoon into the prepared pan and smooth the surface.

Step 4

Bake in preheated oven for 20 minutes or until a skewer inserted into the centre comes out slightly sticky. Remove from oven and set aside in the pan for 3 hours to cool and set. Cut into squares.