1Preheat oven to moderately slow, 160 C. Line 3 oven trays with baking paper.
2Melt chocolate and butter in a small saucepan over low heat, stirring occasionally until melted.
3Sift flour, cocoa and baking powder together onto a piece of baking paper.
4In a bowl, using an electric mixer, beat eggs and sugar together until well combined. On low speed, gradually beat in chocolate mixture and peanut butter.
5Mix in dry ingredients until well combined. Set mixture aside 5 mins until firm.
6Roll tablespoons of mixture into balls. Press tops into icing sugar and arrange on trays, 3 cm apart. Flatten slightly.
7Bake 10 to 15 mins, until cracked and slightly firm on the outside. Cool on trays 5 mins before transferring to wire racks to cool completely.
TIP: These biscuits firm slightly as they cool. Store them in an airtight container.
Photo: Rob Shaw/BauerSyndication.com.au