Do this.
Make a yellow sheet cake. From a box is fine.
As soon as it comes out of the oven, melt a cube of butter all over it. Yes, just unwrap a cube of butter and rub it all over the top of the hot cake. If you want to be “healthy,” use only half of a cube.
Sprinkle cinnamon and sugar all over the melted butter until you have a full layer of buttery-soaked, cinnamon goodness on top of your cake.
Let it cool for a few minutes.
P.S. I first discovered this cake when I worked at a camp in the Texas Hill Country during college. I don’t know where the name came from other than we were in Texas and a lot of people at the camp hailed from Corpus Christi. I usually make this cake every New Year’s Eve for our annual fiesta, but I always forget to share the recipe in the midst of holiday craziness. I figure sharing it for Cinco de Mayo is a good back up option!