1Preheat an oven to 300 degrees F (150 degrees C). Grease a 9x13 inch baking dish.
2Use an electric mixer to beat the 1 egg and the butter in a large bowl. Beat in the cake mix until all crumbs are moistened. Pat mixture into the prepared baking dish.
3Beat the cream cheese, 2 eggs, and confectioners' sugar together in a large bowl. Pour over cake mixture in pan.
4Bake in preheated oven until light golden brown, about 1 hour. Brownies will fully set as they cool. When cooled completely, cut into 1 1/2 inch squares.
Footnotes
Cook's Note
The toothpick test will not work for these brownies. They will be "gooey" until fully cooled.
Tip
Aluminum foil helps keep food moist, ensures it cooks evenly, keeps leftovers fresh, and makes clean-up easy.