Preheat your oven to 350°F (175°C), grease two 8-inch round cake pans and line with parchment paper.

Sift together flour, cocoa powder, sugar, baking soda, baking powder, and salt in a large mixing bowl.

Whisk buttermilk, oil, eggs, and vanilla extract until blended in a separate bowl.

Make a well in the dry ingredients and pour in the wet mixture, folding gently. Gradually stir in hot coffee.

Pour batter into prepared pans and bake for 30-33 minutes, until a toothpick comes out clean.

Allow cakes to cool in pans for 10 minutes, then turn out onto a wire rack to cool completely.

In a saucepan, heat blackberries with sugar, lemon juice, lemon zest, and cinnamon stick until boiling. Mix cornstarch with water and stir into the mixture until thick.

Beat together cream cheese and butter until smooth, then gradually add sifted sugar and cocoa powder until fluffy.

Level cakes, frost the top with cream cheese frosting, and spread blackberry compote. Place the second layer on top upside down.

Frost the top and sides, chill for 30 minutes, and decorate with chocolate skulls, blackberries, and rose petals.