Combine sugar, corn syrup, and water in a heavy saucepan.
Cover and bring to a rolling boil over medium heat.
Remove the lid and continue boiling for 6 - 10 minutes. Do not stir.
Check the mixture using a 1 cup glass measuring cup filled with cold water sitting on the counter next to the pot.
At the 6 minute mark, drop a small amount of the syrup into the cold water. If a firm ball forms, it's ready.
If a firm ball forms, it's ready. If it drops flat or drizzles to the bottom of the cup, cook for 30 seconds more and check again.
If you have a candy thermometer, you want the temperature to be 245 degrees F.
While the mixture is boiling, use the whisk attachment of your mixer to beat the egg whites on high until stiff peaks form.
Once your syrup is ready, turn your mixer on medium speed and slowly (SLOWLY) stream the hot mixture into the egg whites.
When all of the syrup is incorporated into the egg whites, add the vanilla.
Beat on high speed for about 10 minutes or until stiff peaks form.
Spread a little of the fluffy white frosting on top of the bottom layer and sprinkle with coconut.
Add the second layer and spread frosting on top of it and sprinkle with coconut.
Add your third layer and spread the remaining frosting over the top and sides of the cake and add coconut.
Gently press the coconut into the frosting
Now, lick the bowl! Your cake is ready to serve.