Rub the casserole dish with some butter and put the side for later. In a mixing bowl sift the all purpose flour, sugar and baking powder together followed by the raisins and milk. Stir the ingredient into thick batter. Now spoon the pudding batter into the buttered casserole dish.
Taking a clean bowl add the brown sugar, butter and vanilla then pour onto it the boiling water. Let all these ingredients become a liquid then carefully pour the liquid over the top of the batter. DO NOT STIR TOGETHER just leave alone. Now place the casserole dish into the preheated oven and allow to cook for 30 minutes.
Note of wisdom - This is best served warm, if it is served too hot it will definately scald the mouth. Optional: This pudding can also be served with some cream or vanilla ice-cream.