Preheat oven to 350-degrees. Combine the cake mix, egg, and butter and mix well with an electric mixer. Pat the mixture into the bottom of a lightly greased 13 by 9-inch baking pan.
As it is cooking, every once in a while shake the tar out of it, so the center part will stay sort of soft/gooey/runny. When the surrounding edge and part way toward the center gets brown and the center has set up, BUT not firm, it's done. It is supposed to be sort of gooey/sticky in the middle section.
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