Preheat oven to 350°F. Spray a 9 x 13 baking pan with cooking spray. Sprinkle coconut, chocolate chips and pecans into the bottom of the baking pan.
With an electric mixer, combine cake mix with oil, eggs and water (these amounts may not match instructions on the box), using the low setting and beating for 2 minutes. Scrape down the sides and beat 30 seconds more. Spoon the batter carefully over the items in the bottom of the pan without disturbing them.
Place the butter and cream cheese in a small saucepan over low heat until melted, then whisk until smooth. Pour into the large bowl of an electric mixer and beat in the powdered sugar to form a smooth, thick mixture.
Spoon the cream cheese mixture on top of the chocolate batter and draw a knife through to swirl the two mixtures together.
Bake for about 45 minutes. The cake should feel cooked and firm when touched with a finger on top, but it will not respond properly to the toothpick test because the cream cheese mixture inside will still be very soft.
Cool completely on a cooling rack before cutting to serve. This cake should be stored in the refrigerator.