In a large mixing bowl, combine the cake mix, water, oil, and eggs. Stir gently until just blended—about 2 minutes.

Gently fold in the shredded coconut and chopped pecans into the cake batter.

Preheat your oven to 350°F (175°C). Grease and flour your cake pans. Pour the batter into the prepared pans and bake for 17 to 20 minutes.

Once baked, let the cakes cool in the pans for 10 minutes before inverting them onto wire racks.

In a mixing bowl, beat the cream cheese and powdered sugar until creamy. Mix in rum if using.

Once cooled, spread a layer of frosting between the cakes and frost the top and sides of the entire cake.

Refrigerate the frosted cake for at least 2 hours to let the flavors meld.