• Preheat the oven to 350 degrees Fahrenheit. Brush an 8-inch round cake pan with melted butter and line the bottom of the pan with a round piece of parchment paper. Brush the parchment paper with melted butter as well. Set aside.
• In a large mixing bowl, whisk together ½ cup coffee and ½ cup buttermilk. Whisk in ¼ cup vegetable oil, 1 large egg and 1 teaspoon pure vanilla extract. Beat until thoroughly combined.
• Sift 1 cup all-purpose flour, 6 tablespoons cocoa powder, ½ teaspoon baking soda, and ½ teaspoon baking powder into the liquid mixture. Add ¼ teaspoon kosher salt and 1 cup granulated sugar and whisk until a smooth batter forms.
• Transfer the cake batter into the prepared cake pan and bake for 30 - 35 minutes until a toothpick inserted in the middle of the cake comes out clean with just a few crumbs attached.
• Allow the cake to cool in the pan for 10 - 15 minutes before inverting it over and set it on a wire rack to cool completely.

Chocolate Ganache

• To make the chocolate ganache, microwave 4 ounces heavy whipping cream in a heat-proof vessel for 50 - 55 seconds, watching it during the last few seconds to ensure it doesn’t boil over.
• Add 4 ounces dark chocolate melting wafers to a small mixing bowl and pour the hot cream over the chocolate. Allow it to stand for a minute or two before whisking until the chocolate melts completely and the mixture is smooth. Let the ganache cool completely and refrigerate it for about 15 - 20 minutes until it thickens but is still pourable.
• Place the cooled cake on a cake stand or plate and drizzle the ganache over the top of the cake. Tap the cake stand or plate lightly on the table top to even out the top of the ganache. Serve right away or let the ganache thicken further in the fridge before serving.