Instructions:

• Preheat your oven to 350°F (175°C). Grease and flour your two 9-inch round cake pans.
• In a bowl, whisk together the boiling hot coffee and the cocoa powder until smooth. Allow this mixture to cool slightly while you prepare the dry ingredients.
• In a large mixing bowl, sift together the all-purpose flour, sugar, baking powder, baking soda, and salt.
• In another bowl, whisk together the eggs, vegetable oil, Greek yogurt, vanilla extract, and buttermilk. Add the cocoa mixture to this bowl and mix until everything is well combined.
• Gradually add the wet ingredients to the dry ingredients, stirring gently until just combined.
• Divide the batter evenly between the two prepared cake pans. Bake for 30-35 minutes, or until a toothpick inserted into the center comes out clean.
• In a saucepan, whisk together the milk, sugar, cornstarch, vanilla extract, and egg. Cook over medium heat, stirring constantly until thickened. Remove from heat and stir in the finely chopped semisweet chocolate until melted and smooth.
• In a heatproof bowl, combine the chopped semisweet chocolate and a pinch of salt. In a saucepan, heat the heavy cream until just simmering. Pour the hot cream over the chocolate and whisk until smooth and glossy.
• Once the cakes are completely cooled, place one layer on a serving plate. Spread the filling over the top, then carefully place the second layer on top. Pour the ganache over the top, allowing it to drip down the sides.