Place butter and sugar in the bowl and cream for 8 seconds speed 3.
Add egg and mix for 5 seconds speed 3.
Add milk, cocoa and flour and mix for 5 seconds on speed 7
Pour into a oven proof dish or individual oven proof dishes.
Prepare sauce by mixing sugar, cocoa and boiling water in small jug, and then pour sauce over the top.
Transfer to oven and bake for 35 mins on 180 degrees.
Serve while hot with icecream or cream if desired.