01 -
Preheat oven to 350°F. Grease and line two 8-inch round cake pans with parchment paper.
02 -
Sift together all-purpose flour, black cocoa powder, granulated sugar, baking soda, baking powder, and salt in a large bowl.
03 -
In a separate bowl, whisk buttermilk, canola oil, eggs, and vanilla extract until smooth.
04 -
Gradually mix the wet ingredients into the dry ingredients until just combined. Stir in hot coffee gently; the batter will be thin.
05 -
Divide batter evenly between prepared pans. Bake for 30 to 33 minutes until a toothpick comes out clean. Remove from oven and cool completely in pans.
06 -
In a saucepan, combine blackberries, sugar, lemon juice, lemon zest, and cinnamon stick. Simmer over medium heat for 5 to 6 minutes.
07 -
Mix water and cornstarch until smooth, then stir into the blackberry mixture. Cook until thickened. Remove cinnamon stick and chill compote for at least 1 hour.
08 -
Beat softened cream cheese and butter until smooth and creamy. Add powdered sugar, black cocoa powder, and salt, beating until fluffy. Mix in vanilla extract and beat until well combined.
09 -
Level cake layers if necessary. Place one layer on serving plate, pipe a frosting dam along edge, and fill center with chilled blackberry compote.
10 -
Top with second cake layer inverted (bottom side up). Apply a thin crumb coat of frosting and refrigerate for 20 minutes to set.
11 -
Frost the entire cake evenly with remaining frosting. Decorate with chocolate skulls, fresh blackberries, and crushed dried rose petals as desired.