Bake the cake: Prepare the white cake mix according to the package directions and bake in a greased 9×13-inch baking pan.
Poke the cake: Let the cake cool for about 30 minutes. Use the handle of a wooden spoon or a skewer to poke holes throughout the cake, spacing them about 1 inch apart.
Add the gelatin: Stir the raspberry gelatin into the hot water until completely dissolved. Slowly pour it evenly over the cake, allowing it to soak into the holes.
Add the raspberry layer: Warm the raspberry preserves in a microwave-safe bowl for about 30 seconds, or until easily spreadable. Spread evenly over the cake.
Add the topping: Spread the thawed Cool Whip evenly over the raspberry preserves, then sprinkle the shredded coconut over the top.
Chill: Cover and refrigerate for at least 4 hours, preferably overnight, before slicing and serving.