• Oven and Pans – Preheat the oven to 325°F / 165°C. Grease and line three 8-inch cake pans or two 9-inch pans with parchment paper.

Death by Chocolate Cake Batter

• Bloom the Cocoa – In a large mixing bowl, combine: hot water, cocoa powder, instant coffee (optional). Whisk until smooth. Let it cool slightly so it does not cook the eggs.
• Add Wet Ingredients – Add the white sugar and brown sugar to the cocoa mixture and whisk well. Now add the Oil, followed by eggs one at a time. Then, add the vanilla extract and buttermilk. Whisk until smooth and fully combined.
• Add Dry Ingredients — Combine the flour, baking powder, baking soda, and salt, then add them to the wet ingredients. Whisk just until smooth with no lumps. Do not overmix.
• Bake – Divide batter evenly between prepared pans. Bake for 30–35 minutes for 8-inch pans or 28–33 minutes for 9-inch pans. The cake is done when a toothpick inserted in the center comes out with a few moist crumbs. Cool completely before frosting.

Chocolate Buttercream

• Beat softened butter until smooth and creamy, then mix in cocoa powder, powdered sugar, vanilla, salt, and cream until light and spreadable.
• Whip for 2 to 3 minutes until fluffy and smooth. Adjust consistency with a little cream if needed. (Use immediately or keep covered so it does not crust.)

Chocolate Ganache

• In a microwave-safe bowl, add the chocolate and heavy cream - melt until smooth. Then add the butter and corn syrup, and combine well. Allow the ganache to cool until slightly thickened but spreadable consistency. Chocolate ganache adds a rich finish and gives the cake a clean bakery-style look.

Assemble (Stack the layers)

• Level the Cakes – Once completely cooled, level the tops if needed so the layers stack evenly.
• Fill the Layers – Place the first cake layer on a cake board or serving plate and spread an even layer of chocolate buttercream. Add the next cake layer and repeat, finishing with the final layer placed upside down for a flat surface.
• Chill the cake - Refrigerate the stacked cake for about 20 to 30 minutes so the buttercream firms up and the layers stabilize before covering with ganache.
• Cover with chocolate ganache - Once slightly cooled and thickened, pour the chocolate ganache over the top of the cake and use an offset spatula to gently spread it over the top and sides until the cake is fully coated.
• Frost the cake - Apply another smooth layer of chocolate buttercream over the cake and chill briefly again if needed.
• Let the ganache set - Allow the ganache to set at room temperature or refrigerate briefly until firm before slicing and serving.