1. Preheat the oven at 350 degrees F.
2. In a bowl beat together butter, condensed milk and then vanilla extract with an electric whisk.
3. In another bowl sift dry ingredients - all purpose flour, cocoa powder, baking powder and baking soda.
4. Into the wet ingredients add the dry ingredients in two batches along with coco cola or soda which has to be added until the right consistency of the batter arrives and blend well.
5. Grease 2 cake baking trays and fill them half way with the cake batter.
6. Place in the oven and bake for 15 -20 minutes or until the inserted toothpick in the cake comes out clear.
7. Remove onto a wire rack upside down.
8. Decorate the cake with toppings or whipped cream of desired flavor and serve.