Preheat oven to 350°F (175°C). Grease and flour two 9-inch round cake pans.
In a large bowl, whisk together the flour, sugar, cocoa powder, baking powder, baking soda, and salt. Set aside.
In a separate bowl, whisk together the oil, buttermilk, eggs, and vanilla extract. Add the wet ingredients to the dry ingredients and mix until just combined.
Slowly stir in the boiling water until the batter is smooth and glossy. Divide the batter evenly between the prepared cake pans.
Bake for 30-35 minutes, or until a toothpick inserted into the center of the cakes comes out clean. Allow the cakes to cool completely before frosting.
In a medium-sized saucepan, melt the chocolate chips and cream over low heat, stirring constantly. Allow the ganache to cool slightly.
Spread the cooled ganache over the top of one of the cakes, then top with the second cake. Sprinkle the chopped candy bars over the top of the cake.
Serve and enjoy!
Interesting Facts
This cake will stay fresh in an airtight container for up to 5 days.
This cake can be made in advance and stored in the refrigerator or freezer.
This cake can be made gluten-free by substituting a gluten-free flour blend.