Preheat your oven to 350°F (175°C) and prepare two 8-inch round cake pans. Spray them with nonstick spray, then line the bottom with parchment paper.

In a large mixing bowl, sift together the all-purpose flour, black cocoa powder, white granulated sugar, baking soda, baking powder, and salt.

In a separate bowl, whisk together the buttermilk, canola oil, eggs at room temperature, and vanilla extract until fully blended.

Make a well in the center of the dry ingredients, then pour in the wet mixture. Stir gently until just combined, and add in the hot coffee. Mix until smooth.

Divide the cake batter evenly between the prepared pans. Bake for 30-33 minutes or until a toothpick inserted comes out clean. Let them cool in the pans for 10 minutes before transferring to a wire rack.

In a saucepan, combine fresh blackberries, sugar, lemon juice, lemon zest, and a cinnamon stick over medium heat. Bring to a boil, then reduce to simmer. Cook until blackberries release juices, then add cornstarch slurry.

Set aside to cool for at least an hour.

In a large mixing bowl, beat softened cream cheese and unsalted butter until creamy. Gradually sift in the powdered sugar and mix in black cocoa powder, salt, and vanilla extract until smooth.

Level the cooled cake layers with a serrated knife, place one layer on your serving plate, spread half of the blackberry compote on top, and place the second layer on top. Frost the top and sides with frosting.

Decorate with chocolate skulls, fresh blackberries, and dried rose petals to enhance the spooky theme.