Grease one 13x9x2 inch pan. Line with wax paper and grease the paper. Sprinkle coconut & pecans in the bottom of the prepared pan; set aside.
Combine cake mix, eggs, water, in a large bowl; mix according to package instructions. Spoon the batter over coconut and pecans. Combine cream cheese and butter in a saucepan. Cook over low heat stirring often until butter melts and mixture is smooth. Stir in powdered sugar. Spoon the mixture evenly over the batter.
Bake 350 degrees for 40-45 minutes. Cool on wire rack for 10 minutes; invert cake onto a serving plate. Remove and discard wax paper.