You will need:
200g/7oz of dark chocolate
100g/3.5oz butter
100g/3.5oz rice crispies
1 table spoon caster sugar
1 table spoon cocoa powder
1 table spoon golden syrup

1. Put the butter, sugar, cocoa and syrup in a pan and bring to the boil.
2. Melt the chocolate. - You can either put it in a bowl in the microwave, making sure to keep it on half-power and take it out to stir it so it doesn't burn, or put the chocolate in a bowl over a pan of boiling water.
3. Bring the syrup mix off the heat and stir in the chocolate and cereal.
4. Line a shallow baking tray with grease-proof paper and pour in the mixture, making sure it is evenly spread.
5. Put in the fridge to cool.
6. Once set, slice into bars or squares to serve

I like my cakes with a high proportion of chocolate to crunch, so if you prefer, add more cereal.
Butter can be substituted with margerine for vegans.
Crushed biscuits can be used as an alternative to rice crispies.
Add in marshmallows or my favourite, crushed Maltesers!