This slice can be made up to one week ahead - store in an airtight container in the fridge!
440g packet classic chocolate cake mix
½ cup desiccated coconut
125g unsalted butter, melted
3 cups pure icing sugar
50g Copha, melted
½ teaspoon peppermint essence
¼ cup milk
200g dark cooking chocolate, chopped
1 ½ tablespoons vegetable oil
Grease an 18cm x 28cm rectangular slice pan. Line base and sides with baking paper, extending paper 2cm above pan edges.
Place cake mix in large bowl, reserving icing sachet for another use. Add coconut and butter. Stir until well combined. Press mixture firmly over base of prepared pan.
Cook in a moderate oven (180C) for about 15 minutes, or until lightly browned around edges. Remove from oven. Cool.
To make filling, sift icing sugar into a large bowl. Add Copha and essence. Stir in milk to form a thick, smooth consistency. Pour over base in pan. Smooth over top. Refrigerate for 5 minutes.
To make topping, place chocolate and oil in a heatproof bowl. Sit bowl over a saucepan of simmering water. Stir until smooth. Pour over filling and spread evenly.
Refrigerate slice for about 3 hours, or until set. Lift slice from pan. Stand at room temperature for 10 minutes. Cut into squares to serve.
TIP! Copha is available in the refrigerated dairy section of supermarkets. It can be replaced with 2 tablespoons coconut oil.