Chocolate Banana Caramel Cake

Ingredients

• 2 ounces (60g) dark chocolate, chopped
• 3 tablespoons (30g) unsweetened cocoa powder
• 1/2 cup boiling water
• 1/2 cup (120g) unsalted butter, room temperature
• 1 cup (200g) sugar
• 2 eggs, room temperature
• 1 teaspoon vanilla
• 1/2 cup whole milk
• 1 1/4 cups (150g) all-purpose flour
• 1 teaspoon baking powder
• 1/2 teaspoon baking soda
• 1/4 teaspoon salt
• 1 3/4 cups (230g) all-purpose flour
• 3/4 cup (150g) sugar
• 1/4 teaspoon baking soda
• 1 teaspoon cinnamon
• 1/2 cup (120g) unsalted butter, softened
• 3 large (450g) ripe bananas, mashed
• 1/2 cup unsalted butter
• 1 cup maple syrup
• 1/2 cup sugar
• 1 1/2 cups heavy cream
• 1/4 teaspoon coarse salt
• 1 pound (450g) milk chocolate, roughly chopped
• 1/2 pound (225g) salted butter, chopped
• 2 tablespoons corn syrup