Step 1:

Preheat your oven to the temperature listed on the cake mix box. Prepare and bake the white cake in a 9×13-inch pan according to package instructions. Let it cool for about 30 minutes.
Step 2:

Using the handle of a wooden spoon or a fork, poke holes halfway into the cake, spacing them about an inch apart to allow for even absorption.
Step 3:

In a medium bowl, dissolve the raspberry gelatin in 2 cups of hot water, stirring until fully dissolved. Slowly pour the mixture over the cake, letting it soak into the holes.
Step 4:

Warm the raspberry preserves in the microwave for 30 seconds, just enough to soften. Gently drizzle and spread it across the surface of the cake.
Step 5:

Spread the thawed Cool Whip evenly over the raspberry layer.
Step 6:

Sprinkle the shredded coconut over the entire top, pressing lightly so it sticks to the whipped topping.
Step 7:

Refrigerate the cake for at least 4 hours, or overnight if possible, to allow the flavors to fully meld. Serve chilled.