In a clean bowl add in your butter and sugar and whisk properly for 3minutes if you are using a hand mixer, then 40minutes if you are using a whisk.

Break your eggs in a separate bowl, and add into your mixture one at a time and whisk properly, till its smooth.

Sift your flour in a separate bowl and set aside, In a small bowl, pour in your condensed milk and add water, mix properly..

Gently, add in your flour and milk and mix properly, till your batter is smooth and creamy.

In a separate bowl, scoop out 1/3 of your batter, in another separate bowl put 2 tablespoon of cocoa powder, and 2 table spoon of hot water and mix properly. Add the cocoa mixture into the batter and mix properly.

Grease your cake pan properly with butter, you can place a parchment paper and scoop in 3 big tablespoons of the plain batter, and 2 table spoon of chocolate batter on top the plain butter, continue this process until you are done with your batter..

Continue till you have something like this..

Tap the pan on a hard surface twice to remove air bubbles. Preheat oven to 150 degree Celsius and bake for 1hour.