Preheat oven to 350°F (175°C). Grease a 9×13-inch baking dish with butter or nonstick spray.
In a large bowl combine: German chocolate cake mix, Milk, Melted butter, Eggs, Vanilla. Beat until smooth. Pour evenly into the prepared baking dish.
Sprinkle evenly over the batter: Semi-sweet chocolate chips, Milk chocolate chips.
In a bowl combine: Sweetened condensed milk, Coconut, Pecans, Brown sugar, Cinnamon (optional). Mix well. Carefully spoon the mixture evenly over the cake batter. Do not stir.
Place thin slices of butter evenly across the top. As the cake bakes, the butter melts into the topping, creating an incredibly rich texture.
Bake for 45–50 minutes, or until the cake is set around the edges and the center is slightly gooey. The coconut should be lightly golden.
Allow the cake to cool for 15–20 minutes. This helps the chocolate and coconut filling set while remaining wonderfully gooey.
Spoon warm servings into dessert bowls. Top with: Vanilla ice cream, Whipped cream, Chocolate drizzle, Extra toasted pecans, Toasted coconut. Enjoy while warm.
