Preheat oven to 335° (this temperature bakes the cake wonderfully)
Prepare a 13x9 metal baking dish, spray with a baking spray or brush with pan release.
In a large bowl of a mixer, combine all ingredients.
Cake mix, flour, sugar, pineapple juice, egg whites, sour cream, butter, salt, oil and vanilla extract.
Mix on low speed until the mix starts blending, then turn on medium speed and mix for 2 minutes.
Scrape the bowl and under the beater after the first minute to be sure the ingredients combine fully, then continue mixing until well blended.
Pour the cake batter into a prepared 13x9 pan.
Bake at 335° for 30 minutes, and test with a toothpick until it comes out clean. If your oven runs hot start testing at 25 minutes.
Place reserved pineapple on paper towels to absorb liquid so the pineapple won't make the top of the cake wet.
Toast coconut until golden. I linked in the post to instructions on how to do this on the stove and in the oven.
Drain the cherries and place them on paper towels to absorb all liquid.
Sour Cream Frosting: 1/2 cup butter, 1/2 cup sour cream, 3-4 cups powdered sugar, 1 teaspoon vanilla extract. In the bowl of a mixer combine all the ingredients on low speed, then mix on medium-high until smooth and creamy. A tablespoon of pineapple juice or pineapple extract can be added if desired.
Spread the frosting over top of the cooled cake with the back of a spoon, place pineapple pieces like flower petals, and cherries in the center, and then sprinkle toasted coconut around all the pineapple "flowers". Place the cake in the fridge to chill the fruit and set up the frosting so it's firm.
Store cake in the fridge and remove 1 hour prior to serving.