Blackberry Velvet Gothic Cake - Dramatic Halloween Dessert

Ingredients

• 2 cups all-purpose flour
• 1 1/2 cups granulated sugar
• 1/2 cup black cocoa powder
• 1/2 cup cocoa powder
• 1 cup unsalted butter (softened)
• 3 large eggs
• 2 tsp vanilla extract
• 1/4 cup coconut oil or olive oil
• 2 tsp baking powder
• 1 tsp baking soda
• 1/4 tsp salt
• 1/4 cup fresh blackberry puree
• 1 cup buttermilk
• Purple or red food coloring (optional)
• 2 cups fresh or frozen blackberries
• 1/4 cup granulated sugar
• 1 tbsp lemon juice
• 1 tbsp cornstarch
• 1 cinnamon stick
• 2 tbsp water
• 1 cup heavy cream
• 1 1/2 cups semi-sweet or dark chocolate (chopped)
• 1 tbsp unsalted butter (optional)