01 -
Preheat oven to 170C/335F (standard) / 150C/305F (fan forced / convection). Grease a 5-6 cup baking dish with butter.
02 -
Whisk brown sugar and cocoa in a bowl, set aside.
03 -
Whisk flour, baking powder, caster sugar, cocoa powder and salt in a bowl.
04 -
In a separate bowl or jug, whisk together the butter and milk, then whisk in the egg and vanilla.
05 -
Pour the egg mixture into the flour mixture. Mix until combined - it will be a thick batter. Spread into the prepared baking dish.
06 -
Sprinkle the sugar/cocoa mixture over the batter. Shake gently to spread it out thinly.
07 -
Carefully pour the hot water over the back of a dessert spoon all over the top of the pudding (this helps create a smooth surface).
08 -
Transfer to oven and bake for 30 minutes, or until the top of the cake springs back when poked lightly. The top will be a bit crusty, like the top of brownies.
09 -
Remove from oven, stand for just a few minutes (no more!), then serve immediately while warm to enjoy the sauce.