Place 1 package lemon cake mix in a 9″ by 13″ pan. Make a well in the center of the cake mix.
Pour 3 eggs, 1/3 cup vegetable oil, and 12 ounces Mello Yellow soda into the well. MIx until blended.
Fold in an 8 oz. can of crushed, drained pineapple. Spread the batter evenly and bake according to package directions (should be approximately 45 minutes).
Once the baking is done, poke holes inside it with a wooden spoon.
Drizzle a 14 oz. can of sweetened, condensed milk over the cake. Allow it to cool.
Spread an 8 oz. tub of whipped topping over the cake.
Top with 1/2 cup flaked, toasted coconut. Refrigerate for at least 2 hours.