I have made this a few times and my family loves these. I also used peanut butter mix and sugar cookie mix. I got this from the betty crocker site.

2 cup cold butter
1 pouch (1 lb 1.5 oz) Betty Crocker® oatmeal chocolate chip cookie mix
1 egg
2 packages (8 oz each) cream cheese, softened
1 cup sugar
2 eggs
1 teaspoon vanilla

1. Heat oven to 350°F. Spray bottom of 13x9-inch pan with cooking spray.
2. In large bowl, cut butter into cookie mix using fork or pasty blender. Stir in 1 egg until mixture is crumbly. Gently spoon 3 cups crumb mixture into pan; press into bottom of pan. Bake 15 minutes.
3. In small bowl, beat cream cheese, sugar, 2 eggs and the vanilla with electric mixer on medium speed until smooth. Pour over cookie crust. Spoon remaining crumb mixture over cream cheese.
4. Bake 25 to 30 minutes or until golden brown and firm to the touch. Cool 30 minutes. Refrigerate at least 2 hours or until chilled. For bars, cut into 9 rows by 4 rows. Store covered in refrigerator.
High Altitude (3500-6500 ft): Heat oven to 375°F.