1. Heat oven to 350 degrees F. In a medium bowl, beat butter and cream cheese with an electric mixer for 30 seconds. Add granulated sugar and salt. Beat until combined, scraping sides of bowl occasionally. Beat in egg and 2 teaspoons vanilla until combined. Beat in as much of the all-purpose flour and white whole-wheat flour as you can with the mixer. Stir in any remaining flour. Stir in the chocolate chips.
2. Shape dough into 1 1/2-inch balls. Place 2 inches apart on ungreased cookie sheet. Bake for about 15 minutes, or until bottoms are golden. Transfer to a wire rack and let cool.