Neiman Marcus Bars

1 (18.25 ounce) box yellow cake mix
1 egg, beaten
1/2 cup (1 stick) melted margarine
1 box confectioners' sugar
2 eggs, beaten
8 ounces softened cream cheese
1 teaspoon vanilla extract

Mix cake mix, egg and margarine, Press into the bottom of a 13 x 9-inch pan. Mix remaining ingredients and pour on top of the first layer. Bake at 355 degrees F for 45 minutes.