Lets make the wet ingredient first. In a bowl add 3 eggs, 4 tbsp milk, 2 tsp vanilla essence and whisk it well. In another bowl, add 3/4 cup unsalted butter and whisk it well. Now gradually add 2 cup white sugar and keep whisking it. Now add 2 cup brown sugar and keep whisking it.
After this procedure, pour the egg mixture on the butter mixture and whisk it well. Set aside.

In cake tin, brush it with oil or butter then sprinkle some flour and mix it well until flour has dissolve all oil. This is the alternative option you could use if you don't have baking paper.

Lets start with dry ingredient. In a separate bowl add 1 & 1/2 cup flour, 1 tsp himalayan pink salt, 2 tsp baking powder, 1 cup cocoa powder. Mix it with spoon. Now lets mix the dry and wet together. In the wet ingredient bowl, gradually add dry batter and whisk it slowly and carefully with normal pace. Until smooth consistency is formed of cake batter. How to check for consistency when you use the plastic spatula and pour the cake batter in to tin lid. It will be of slightly thick consistency

Now bake the cake in preheated oven. I just added white chocolate crumbs on the cake batter, so the small holes were made as the cake got baked. You can try making the white chocolate sauce and pour it on top of cake when it is baked and garnish as you like.