Preheat oven to 350 degrees and lightly grease 9x13 inch pan.
Blend with electric mixer on low speed for 1 minute the cake mix, sour cream, cream of coconut, oil and eggs. Scraped down sides of bowl and increase mixer speed to medium and blend for 2 additional minutes.
Pour the batter into the prepared pan and bake 40-42 minutes. Remove from oven and let cool on a wire rack for 20 minutes.
For frosting: Beat cream cheese with electric mixer on low for 30 seconds, add the powdered sugar, milk and vanilla. Beat on low until the ingredients are moistened 30 seconds more. Beat on medium speed until combined and fluffy 2 additional minutes. Spread on cooled cake and top with coconut. You can toast the coconut if you prefer.