Heat oven to 180 degrees celcius.
Mix together sugar, flour, baking powder, cocoa, and salt.
Add in the egg, milk and oil and stir until combined.
Place in an oven proof dish.
In another bowl combine the cocoa and sugar.
Sprinkle over the top of the batter.
Pour over the hot water.
Bake for around 35 minutes - the cake should rise to the top and the sauce will be underneath! Serve hot! You can also reheat this
