Watermelon Flavored Cake | When I told My oldest daughter that I was decorating a cake to look like a watermelon, she excitedly asked, "Will it taste like watermelon too?" That girl seriously loves watermelon! Umm... could I make a cake that tastes like watermelon? After some brainstorming and research, the answer is "Yes!". Watermelon puree and Jell-O give this cake it's flavor, and it is fantastic! And the frosting is SO good...I just want to eat it with a spoon!