Preheat your oven to 350°F (175°C).

Grease and line a 9×13-inch baking pan with parchment paper. 

In a large mixing bowl, combine the devil’s food cake mix, eggs, milk, and vegetable oil. 

Beat with an electric mixer on medium speed until the batter is smooth and well combined.

Pour the batter into the prepared baking pan.

Bake for 30 to 35 minutes, or until a toothpick inserted into the center comes out clean.

Allow the cake to cool completely in the pan.

In a medium bowl, mix together the sweetened flaked coconut, sweetened condensed milk, powdered sugar, and vanilla extract until well combined. 

Once the cake has cooled, spread the coconut filling evenly over the top. 

Refrigerate the cake to set the filling while preparing the ganache.

In a microwave-safe bowl, heat the heavy cream until hot but not boiling.

Add the semisweet chocolate chips to the hot cream. Let sit for 2 to 3 minutes, then stir until the mixture is smooth and glossy. 

Remove the cake from the refrigerator.

Pour the chocolate ganache over the coconut filling, spreading it evenly with a spatula. 

For added texture and flavor, toast additional shredded coconut in a dry skillet over medium heat until golden brown. Sprinkle over the ganache before it sets. 

Refrigerate the cake until the ganache is firm.

Once set, slice the cake into squares and serve chilled or at room temperature.