Chocolate Blackberry Elegantly Gothic Halloween Cake

Ingredients

• 11/16 cup cocoa powder sifted
• 6 tablespoons boiling water
• 4 teaspoons gel food colouring black, optional
• 7 tablespoons softened butter ⅓ cup + 1 heaped tbsp
• 3/4 cup light brown soft sugar
• 7/8 cup caster sugar
• 1 3/8 cups self raising flour 1 + ½ cups, sifted
• 1 baking powder rounded tsp
• 3 large eggs beaten
• 7/8 cup dark chocolate chopped
• 7 1/16 tablespoons white chocolate chopped
• 1/2 teaspoon food colouring purple powdered, optional, DO NOT use water based colouring, including gel, powdered or oil based only
• 2 15/16 cups blackberries fresh or frozen
• 4 tablespoons sugar
• 13/16 cup egg white 5 large
• 2 1/4 cups caster sugar 1 + ⅓ cup
• 1 2/3 cups softened butter 1 + generous ½ cup
• 4 3/8 ounces blackberry puree ⅓ + ⅛ cup
• 1 teaspoon vanilla extract
• 1 teaspoon food colouring purple gel or powdered, optional
• 5/8 cup dark chocolate chopped
• 3 1/2 ounces blackberry puree generous ⅓ cup
• 2 tablespoons full-fat milk plus extra as needed
• 2 1/8 tablespoons butter
• 1 teaspoon gel food colouring black, optional
• 4 tablespoons blackberry jam
• fondant black, for the roses
• silver lustre dust
• purple sprinkles black and, as desired