Preheat the steamer.

In a bowl, add-in the vinegar, evaporated milk, and water. Mix until well-blended. Set aside.

In a separate large bowl, sift-in the all-purpose flour, cocoa powder, baking powder, and baking soda. Then add-in the sugar, and salt. Mix until well-incorporated. Set aside.

In another bowl, add-in the eggs, vanilla extract, and the milk mixture. Whisk continuously while slowly adding in the flour mixture, until well-incorporated.

In a baking pan or cake pan lined with wax paper and greased with oil, transfer the batter and cover the pan with aluminum foil. Steam for 50 minutes.

Transfer to a serving plate or serving tray. Set aside.

In a mixing bowl, add-in the evaporated milk, sugar, all-purpose cream, cocoa powder, and all-purpose flour. Mix until well-incorporated.

In a cooking pot over medium heat, strain the mixture and cook for 3 - 5 minutes. Add-in the butter and cook until the mixture becomes thick. Set aside and let it cool.

Cut the cake in half lengthwise and then spread the frosting on top of one half, and then place the other half on top of the frosting. Then spread the frosting on top once again, and also the sides until coated.

Let it chill. Serve and enjoy!