Preheat oven to 350 F (180 C). Prepare two 8-inch pan or three 6-inch cake pan with non- stick pan spray or home made pan release. Set aside
In a large bowl, combine the brown sugar, white sugar with softened butter. Whisk till everything is combined.
Add the eggs, buttermilk, vanilla extract, and continue to mix until well combined.
Add the flour, baking powder, baking soda, salt and cocoa powder and mix to combine.
Pour the melted chocolate into the mixture and mix until just combined. Donut over mix the cake batter.
Divide the batter among the prepared pans.
Bake the cakes for about 35 minutes, or until a tester/ toothpick comes out clean or with few crumbs.
Allow the cakes to cool in the baking pan for about 10 minutes before transferring them to wire rack to cool completely.
For The Chocolate ganache
In a heavy pan, pour milk into it and heat on a medium heat until it start to bubble. Stir to prevent scorching and pour over the hot milk over the chocolate discs or chips and butter.
Use a whisk or rubber spatula, stir until all the chocolate pieces are melted. Add the salt and vanilla extract to the ganache and mix until smooth and creamy.
Allow to the ganache to rest and firm up and use for filling cakes or icing cakes.
Assembling the Cake
To assemble the cake, place a nonslip mat on a turntable and then tape a 6 inches cake cardboard circle to an 8 inches cardboard circle (the 8 inches cardboard helps to transport the cake to the fridge and back easily) and place the cake board on the turntable.
Apply a small amount of buttercream to the center of the 6 inches cake board. Place the first cake layer on the board, add a thin layer of chocolate jam. Add a buttercream dam and add enough chocolate ganache onto the cake and smooth as level as you can get. Repeat with the remaining two cake layers.
The last cake layer should be placed flat side up that is the bottom should face up. Press down on the stacked cakes lightly to help the cakes stick to the icing. Crum coat and chill for 30 minutes or freeze for 5 minutes.
Add a layer of buttercream or chocolate ganache and smooth the sides of the cake with cake scraper or bench scraper.
Decorate it as you like and serve to enjoy. I used the cake as a base for a mirror glaze cake and finished with chocolate flower.
I decorated it with mirror glaze and chocolate flower but this cake can be made to any design you prefer. The chocolate ganache can be used as the finish on the cake too.