01 -
Preheat oven to 175°C (350°F). Grease a 23×33 cm (9×13 inch) baking dish with butter or nonstick spray.
02 -
In a large bowl, combine cake mix, whole milk, melted butter, eggs, and vanilla extract. Beat until smooth. Pour evenly into prepared baking dish.
03 -
Sprinkle semi-sweet and milk chocolate chips evenly over the batter.
04 -
In a separate bowl, mix sweetened condensed milk, shredded coconut, chopped pecans, brown sugar, and ground cinnamon (if using) until well combined.
05 -
Carefully spoon the coconut pecan mixture evenly over the chocolate chip layer without stirring.
06 -
Distribute thin slices of unsalted butter evenly over the top of the coconut pecan layer to enrich the texture as it bakes.
07 -
Bake in the preheated oven for 45 to 50 minutes until the edges are set, the center is slightly gooey, and the coconut is lightly golden.
08 -
Allow to cool for 15 to 20 minutes to let the filling set but remain gooey. Serve warm in dessert bowls and optionally garnish with vanilla ice cream, whipped cream, chocolate syrup, toasted pecans, toasted coconut flakes, and chocolate shavings.