Chocolate Pan Cake - cooking recipe

Ingredients

4 ounces butter
1 cup water
3 tablespoons cocoa powder
1 tablespoon baking powder (raining agent)
2 cups flour (plain)
2 cups sugar (white)
1/2 cup milk
1 teaspoon baking soda
1 tablespoon vinegar
2 large eggs (beaten)
1 teaspoon vanilla
Chocolate Pan Cake Frosting
3 ounces butter
3 1/2 tablespoons milk
3 tablespoons cocoa powder
1 cup powdered icing sugar

Preparation

Melt butter, water and cocoa; bring to boil.
Mix together in a bowl: baking powder, flour and sugar; pour in boiling liquid.
Mix together milk, soda and vinegar; pour into batter. Add eggs and vanilla (batter will be very runny).
Pour into an oblong UNGREASED pan 9\"x12\"x2\".
Cook in preheated oven on 180\u00b0C (400\u00b0F) for 30 minutes or until cake springs back when touched.
When cooked remove from oven and cut into 15 squares (while still hot); leave in pan.
Frosting: Melt butter. Add milk and cocoa, then add sugar gradually; stir until shiny.
Pour frosting over cut cake.
Let stand until cool, then refrigerate-- Keep in fridge.