Philadelphia Style Butter Cake

1 large egg
1 (18.25 ounce) box yellow cake mix
1/2 cup butter, softened
8 ounces cream cheese, softened
1 pound confectioners' sugar, sifted
2 large eggs
1 teaspoon vanilla extract

Heat oven to 350 degrees F. Grease and flour a 13 x 9-inch cake pan.

Beat together the 1 egg, cake mix and butter for 5 minutes. Mix and pour into prepared pan.

Cream together cream cheese, confectioners' sugar, the 2 eggs and vanilla extract. Pour this on top of the cake base.

Bake for 35 to 40 minutes until browned. Cool for 15 minutes, and cut into squares.