Preheat oven to 180 C / Gas 4. Grease and flour one 20cm square baking tin.
Sieve the flour, cornflour, sugar, 3 tablespoons cocoa, baking powder, bicarbonate of soda and salt together. Make a well in the centre and add the water, oil, vinegar and vanilla. Beat until smooth and pour batter into the prepared tin.
Bake in preheated oven for 30 minutes. Let cool.
Meanwhile, combine the 45g cocoa powder, sweetened condensed milk and butter in the top half of a double boiler and cook until thick. Spread warm mixture over the top of a slightly cooled cake.
Loved it made if for my sons birthday cake as he's allergic to egg. When I asked people if it tasted different nobody could tell it was made without egg. Perfect. Thanks for the recipe.
Made this cake again as my sons school are doing a party and didn't want him left out. Came out even better then last times. Tastes so good - 21 Nov 2013