1. Pre-heat oven to 180°C.
2. Place butter and chocolate in a saucepan and melt over a very low heat until the mixture becomes just smooth.
3. Place eggs and sugar in a bowl and beat until pale and thick.
4. Mix in the flour and nuts with a wooden spoon then fold in the chocolate mixture. To finish, pour over the Coco Pops and gently press into the top of the brownie mix.
5. Divide the mixture in half and pour each half into a 20cm square cake tin lined with greaseproof paper.
6. Bake in the oven for 30 minutes or until firm to the touch.
7. Cut into 24 squares and store in an airtight container for up to 1 week.