1 (3.4-ounce) box instant lemon pudding mix
4 large eggs
3/4 cup vegetable oil
1 1/4 cups 7-Up soda
Pineapple-Coconut Frosting:
1 1/3 cups granulated sugar
2 tablespoons flour
2 large eggs, lightly beaten
1/2 cup butter, cut into 1 tablespoon pieces
1 (20-ounce) can crushed pineapple, undrained
1 cup sweetened shredded coconut
Preheat oven to 350 degrees and spray a 9x13-inch pan with cooking spray. Using an electric mixer, beat cake mix, pudding mix, eggs, and vegetable oil until well mixed. Beat in 7-Up until batter has an even consistency. Pour batter into prepared pan. Bake for 30 to 35 minutes or until cake feels firm when you press on the top. Prepare the frosting while the cake is baking. In a medium saucepan, whisk together the sugar and flour. Add the eggs, butter, and pineapple and cook over medium-low heat, stirring constantly, until mixture thickens up. Remove from heat and stir in the coconut. Pour over cake. Store cake in refrigerator.