First let's make chocolate ganache. In a bowl take amul cream and heat it until warm, don't boil it. In another bowl take 250 grams of chocolate compound and melt it either by double-boiler method or microwave it for about 30 to 40 secs. Now add this hot cream into the melted chocolate and start mixing it immediately until it's completely mixed and gets combined with each other. Your chocolate ganache is now ready. Now keep this in a refrigerator to set.

In a small bowl/cup, add half cup of hot milk. Then add 1 tsp of vinegar in it. Mix it well. Now cover it and keep it aside for 10 mins. After 10 mins. it will form buttermilk, as shown in the image below.

Now transfer this buttermilk mixture into a large mixing bowl. Then add butter and vanilla essence in it. Whisk everything well.

Now keep a strainer over the bowl and add all the dry ingredients like maida, powdered sugar, cocoa powder, baking powder & baking soda. Strain them and start mixing them by using cut and fold method. Now add 1/4th cup of milk to make a smooth cake-batter. Now add some choco-chips (optional) & give it a mix.

Now heat a kadai for pre-heating with it's base covered with salt and a stand over it. Cover it and pre-heat the kadai for 5 mins on high flame and then 3 mins. on medium flame.

Until the kadai is getting pre-heated, let's grease a cake-tin mould. Then cover it with a butter paper & again grease the butter paper by brushing some oil over it. Now pour the cake batter in it.

After 8 mins of pre-heating, open the lid and place the cake-tin over it. Immediately cover the lid. Now bake the cake over a low flame for 35 to 40 mins. Check it will the help of a tooth pick. If it comes out clean, then it's done. Now remove it from the kadai. Let it cool down completely then de-mould it.

When it cools down completely, cut it into halves, with the help of a thread. Now let's make sugar syrup. For making syrup, in a cup just add 2 tbsp of sugar to it add 1/4th cup of lukewarm water. Give it a good mix. Now keep this sugar syrup aside.

Then brush this sugar syrup over the two of the cake (which you have divided into 2) Now apply a thick layer (1 cms nearly) of chocolate ganache, which you have prepared earlier (mentioned in step 1).

Then sprinkle some choco-chips & roasted walnuts over it. (dry-roast the walnuts in a pan so that it becomes crunchy) Then again keep the second half over it. Again brush some sugar syrup over it. Then again apply a layer of chocolate ganache. Spread it evenly and now cover the complete cake (even on the sides) with the ganache by gently leveling it.

Now keep it inside the refrigerator for 15 to 20 mins. to set it. Then after 15 mins remove the cake. Now heat the remaining ganache for 10 to 15 seconds, it will become pouring consistency now. Then pour this ganache over the cake to give it a final touch. Now donot use any spatula to level it. The ganache will slowly flow over the cake and settle down by its own. Now again keep it inside the refrigerator to set it completely.

Then remove it and decorate it with some choco-chips or with some designs of your choice. I have decorated it with some choco-chips, some chocolate joy-sticks & with some edible flowers. You can decorate it, as per your wish.