530g packet rich chocolate cake mix
½ cup vegetable oil
100g dark cooking chocolate, coarsely chopped
100g milk cooking chocolate, coarsely chopped
Grease two large oven trays. Line with baking paper.
Place cake mix in a large bowl, reserve frosting sachet for another use. Add oil and egg. Stir with a wooden spoon until well combined.
Roll heaped tablespoons of mixture into balls. Place about 6cm apart on prepared trays. Using your fingertips, flatten and shape balls into 6cm rounds. Gently press chocolate pieces into the tops.
Cook in a moderate oven (180C), swapping trays halfway, for about 10 minutes, or until chocolate pieces are lightly browned. Remove. Stand biscuits on trays for 15 minutes.
Transfer to a wire rack to cool completely before serving.
TIP! Biscuits can be made up to two weeks ahead. Store in an airtight container. Replace chocolate with 200g of your favourite chopped chocolate bar. Try Toblerone, Picnic or Mars Bars.