Neiman Marcus Bars

1 box yellow cake mix
1 stick margarine, melted
1 egg
1 cup chopped nuts
1 package (8 ounces) cream cheese
2 eggs
1 box (16-ounce) powdered sugar
1 teaspoon vanilla

Preheat oven to 350 degrees. Stir together cake mix, margarine, 1 egg and nuts, then press into a 9-by-13-inch pan. Cream together cream cheese, 2 eggs, powdered sugar and vanilla, then pour over cake mixture. Bake for 40 minutes. Cool thoroughly (refrigerate) before slicing into bars.