No one knows who (or which baking-related company) created the recipe for the first flag cake. There is an ongoing battle of wills between Ina Garten and Martha Stewart over the claim. Calling it a feud feels too strong, and the history of this cake and these women is deeply intertwined. Regardless, Americans have been making some variation on the idea of a flag cake for generations. Long story short, the true origin of the flag cake is unknown and, as the Onion cleverly noted two decades ago, most of us don’t know why we make them anymore.
Let’s start with the Ina vs. Martha of it all, as their iterations of the flag cake have become the definitive model of the current era. Both have authored a white, vanilla sheet cake topped with stars and stripes made from blueberries, raspberries or sometimes strawberries, and buttercream frosting. In putting it together, both of them were thinking about featuring the fruits of the season at their peak, as long as you stick to strawberries for your Memorial Day flag cake and swap them for raspberries for the Fourth of July. The buttercream frosting is also smart, because it holds up to heat so well — it may sweat, but it won’t run like a normal icing when you set this cake outside at the cookout. And because most of us don’t want to stand over a hot oven during summer, a simple sheet cake is as minimal as a bake can get.