Preheat oven to 350 degrees F (175 degrees C).
Prepare three 8 or 9-inch round cake pans with Butter (to taste) and Granulated Sugar (to taste).
In a mixing bowl, combine the Lemon Cake Mix (1 box), Instant Vanilla Pudding (1 box), Vegetable Oil (3/4 cup), 7UP® (7 fluid ounce), Pineapple Juice (3 fluid ounce), and Egg (4). Beat on medium speed until well blended, about 2-3 minutes. Divide evenly into the three pans.
Bake for 30 minutes until toothpick inserted in center comes out clean.
Cool in the pans for 5 minutes, invert and let cool completely.
In a medium sauce pan, combine Granulated Sugar (1 1/2 cup), Butter (8 tablespoon), and Pineapple (1 cup) with the juice and the beaten eggs. Cook over low to medium low heat, stirring constantly. Increase heat to medium and cook until thick and bubbly. Remove from heat and stir in the bag of Sweetened Coconut Flakes (1 bag).
Spread the warm icing over the cake layers and enjoy!