1. Place chocolate and butter in bowl over a saucepan of simmering water until melted.
2. Remove from heat and stir in sugar.
3. Add eggs and vanilla and beat well.
4. Sift the flour and baking powder into a large bowl.
5. Add the chocolate mixture and stir well.
6. Cover with plastic wrap and chill for 1 hour.
7. Preheat oven to 160C.
8. Line a baking sheet with non stick paper.
9. Place icing sugar in a bowl.
10. Form heaped teaspoons of dough into balls and roll in icing sugar.
11. Place on tray, slightly flatten and bake in oven for 10-15 minutes until tops of biscuits crack.
12. They will be soft when removed, but will harden upon cooling.
13. When cool, sandwich icing between two biscuits.
14. Decorate cookies with a drizzle of dark chocolate and CADBURY MINI EGGS chocolate eggs.