Preheat your oven to 350°. Break up the bar of Green & Black’s Dark Chocolate and place in a large bowl (or bowl of your stand mixer). In a small saucepan on medium heat add butter, milk, and white sugar. Cook mixture while stirring until sugar is dissolved, about 2 minutes. Pour over the chocolate and mix with a spoon until the chocolate is completely melted. Allow to cool for 5 minutes, then, while mixing on low speed, add vanilla and eggs. Continue to mix until well combined.