Gently melt butter on a low heat ( about 1/2 pack )
As it starts to melt add Milk Drink Choc powder about 10 tbls and about 5 tbls of dark drinking choc powder.
Keep mixing slowly to prevent lumps and to blend the powders.
Once most of the butter has melted, add Golden Syrup about 1/2 the qty of the butter.
Let the mixture melt but no hotter than all melt. The temp is key to this working. If it becomes too hot it will not set after.
Add corn flakes a little at a time and gently fold them to cover them with the mixture. The ratio of flakes to mix is to your taste.
Put in a tray, let cool then in fridge.