Step 1: Preheat your oven to 350°F (175°C). Grease and flour two 8-inch round cake pans.
Step 2: In a large bowl, whisk together the flour, 2 cups sugar, cocoa powder, baking soda, baking powder, and 1 teaspoon salt.
Step 3: In a separate medium bowl, whisk together the buttermilk, vegetable oil, eggs, and vanilla extract.
Step 4: Add the wet ingredients to the dry ingredients and mix on low speed with an electric mixer until just combined.
Step 5: Slowly pour in the hot brewed coffee and mix until the batter is smooth. The batter will be thin.
Step 6: Divide the batter evenly between the prepared cake pans. Bake for 30-35 minutes, or until a wooden skewer inserted into the center comes out clean.
Step 7: Let the cakes cool in the pans for 10-15 minutes before inverting them onto a wire rack to cool completely.
Step 8: To make the Caramel Soak: In a small saucepan, combine 1/2 cup sugar and 1/4 cup water. Bring to a boil over medium-high heat, stirring until the sugar dissolves. Continue to boil without stirring until the mixture turns an amber caramel color (this usually takes 5-8 minutes).
Step 9: Remove the saucepan from heat. Carefully and slowly whisk in the 1/4 cup heavy cream, unsalted butter, and a pinch of salt. Be cautious, as the mixture will bubble up vigorously. Let the caramel soak cool slightly.
Step 10: Once the cakes are completely cool, use a skewer or fork to poke holes evenly over the top of each cake layer. Pour half of the slightly warm caramel soak over each cake layer, allowing it to absorb fully.
Step 11: To make the Chocolate Drizzle: Place the finely chopped bittersweet chocolate in a heatproof bowl. Heat the 1/2 cup heavy cream in a small saucepan until it is just simmering. Pour the hot cream over the chocolate and let it sit undisturbed for 5 minutes.
Step 12: Whisk the chocolate and cream together until the mixture is smooth and glossy. Let the ganache cool slightly to a drizzly consistency.
Step 13: To assemble: Place one caramel-soaked cake layer on a serving plate. Pour about half of the chocolate drizzle over the top, spreading it gently. Place the second cake layer on top and pour the remaining drizzle, allowing it to elegantly drip down the sides of the cake.
Step 14: Refrigerate the cake for at least 30 minutes to allow the chocolate drizzle to set. Slice and serve your decadent creation! Enjoy!