Chocolate Toffee Crunch Cake

Ingredients

• 1 ½ cup coffee (or water)
• ¾ cup unsalted butter
• ½ cup unsweetened Dutch-processed cocoa powder
• 3 large eggs
• ¾ cup buttermilk
• 2 tablespoons grapeseed or canola oil
• 2 teaspoons vanilla extract
• 3 cups all-purpose flour
• 2 cups granulated sugar
• 1 ½ teaspoons baking soda
• ½ teaspoon baking powder
• 1 teaspoon salt
• 1 teaspoon cinnamon
• 6 large egg whites
• 3 cups unsalted butter, softened
• 2 teaspoons vanilla extract
• 5 ounces chocolate, melted and cooled
• 4 tablespoons unsalted butter
• ½ cup granulated sugar
• ½ teaspoon cinnamon
• ¼ teaspoon salt
• ½ cup water
• 1 cinnamon stick, crushed