In a mixing bowl add the buttermilk, sugar, oil, vanilla extract, stir and mix well.
Sieve the flour, cocoa powder, milk powder, baking powder, baking soda and salt atleast twice to incorporate them well.
Preheat the oven @180° for 10 minutes. Grease the cake pan and line with butter paper.
Add the dry ingredients into the wet ingredients and gently fold to make a smooth batter.
Pour the batter into the greased pan and tap the pan to release the air bubbles.
Bake at preheated oven @180° for 30-35 minutes. A toothpick inserted should come out clean. Check from 30 minutes onwards.
Remove from the oven, let it stand for 5 minutes. Demould and allow the cake to cool down completely.
Making Chocolate Ganache:Place chocolate pieces in a large bowl. Heat cream on medium high until it comes to a boil. Remove from heat and immediately pour cream over chocolate. Let it stand undisturbed for few minutes..
Now add vanilla extract if using and stir until completely mixed and glossy. Allow ganache to cool and refrigerate atleast 2-3 hours before frosting the cake.
Remove the ganache from refrigerator few minutes before frosting the cake. Whisk them for 2-3 minutes until fluffy and your ganache is ready for filling, pipping and frosting.
Once the cake is completely cooled down. Cut the cut into 2 layers.
Take one layer of the cake and apply the sugar syrup. Now spread the ganache evenly over the cake. Top with another layer of the cake and spread the ganache all over the cake including the sides and evenly spread and cover the cake.
Smoothen the Ganache using scrapper or palette. Decorate the cake as per your choice.
Allow the cake in refrigerator for 20-30 minutes for clean cut finishing. Enjoy.