• To begin, preheat the oven to 350º F and prepare two 8-inch round baking pans.
• Next, chop the chocolate and melt it in a saucepan over medium-low heat, then set it aside to cool to room temperature.
  
• In a small bowl, sift together the flour, cocoa, baking soda, and salt.
• In a separate bowl, whisk together the brown sugar, softened butter, eggs, espresso, and vanilla extract for about 3 minutes.
• If using a hand-held mixer or stand mixer, this step should take about 1 minute. Gradually add the melted chocolate and continue whisking for an additional minute.
• Stir the flour mixture into the creamed mixture and then add the buttermilk.
• Pour the batter into the prepared pans and bake for 33 to 38 minutes, or until a wooden pick inserted in the centre comes out somewhat clean.
  
• Let the cakes cool in the pans on wire racks for 10 minutes, then run a knife around the edges of the cakes and invert them onto wire racks to cool completely.

Making Ganache

• For the ganache, place the chopped chocolate in a medium bowl.
  
• Heat the cream in a small saucepan over medium heat, being careful not to let it boil for more than a few seconds as it can burn.
• Pour the hot cream over the chopped chocolate, let it sit for a few minutes, then whisk until smooth.
  
• Allow the ganache to cool slightly before pouring it over a cake.

Frosting and Assembling The Espresso Chocolate Chip Cake

• Just enough coffee buttercream is produced to fill the cake, gently frost the outside, and pipe a simple border around the top. Although they make for a tasty garnish, chocolate-covered coffee beans are optional. Alternatively, decorate the cake with chocolate sprinkles, chips, or curls.