Preheat the oven to 350°F (180°C). Butter and line 2 round cake pans.
Sift the flour, sugar, cocoa, baking soda, baking powder, and salt into a large bowl. Whisk the ingredients together by hand.
In another bowl, combine the buttermilk, oil, eggs, vanilla and coffee
Add the wet ingredients to the dry and GENTLY mix the batter just to combine. Do not over mix or beat as this cake can toughen up.
Pour the batter into the prepared pans and bake for 30 to 35 minutes, until a tooth pick inserted comes out clean.
Cool in the pans for 30 minutes, then turn them out onto a cooling rack and cool completely.
cut the cake in half and keep aside for spreading the frosting
Chocolate buttercream frosting
Cream together butter and cocoa powder until well-combined.
Add sugar and milk to cocoa mixture by adding 1 cup of sugar followed by about a tablespoon of milk. After each addition has been combined, turn mixer onto a high speed for about a minute. Repeat until all sugar and milk have been added.
Add vanilla extract and combine well.
If frosting appears too dry, add more milk, a tablespoon at a time until it reaches the right consistency. If it appears to wet and does not hold its form, add more sugar, a tablespoon at a time until it reaches the right consistency
To Frost
Place 1 layer, flat side up, on a flat plate or cake pedestal.then level it by cutting top and crumble it.
With a knife or offset spatula, spread the top with frosting. Place the second layer on top, rounded side up, and spread the frosting evenly on the top and sides of the cake.
Then put the remaining frosting in piping bag and pipe on the top in swirl type and in gaps add the crumbled cake on it.
Store at room temperature or in the fridge.make sure it reaches room temperature before eating.