Preheat your oven to 350°F. Bake the chocolate cake according to package instructions in a greased 9×13-inch pan. Allow to cool for about 10 minutes.
Use the handle of a wooden spoon to poke holes evenly across the cake. Slowly pour the sweetened condensed milk into the holes, letting it soak through.
Drizzle the caramel sauce evenly over the cake, allowing it to seep into the surface.
In a saucepan, melt butter, then stir in the coconut and chopped pecans. Cook until warm, then spread the mixture evenly over the cake.
Heat heavy cream in a saucepan until just simmering. Pour over the chocolate chips and let sit for 2–3 minutes. Stir until smooth, then mix in vanilla extract.
Spread the ganache evenly over the coconut-pecan layer. Sprinkle with extra pecans or chocolate chips if desired.
Refrigerate for at least 2 hours before slicing. Serve chilled for the best texture and flavor.