Combine butter, cream cheese, sugar and egg until smooth. Add vanilla and orange peel; beat well.

In separate bowl, combine flour and salt; add to creamed mixture and blend well. Stir in chocolate chips. Drop by teaspoonfuls onto an ungreased cookie sheet. Bake at 350 degrees for 15 minutes or until edges just begin to brown. Cool on rack and store in airtight cookie tin. Makes 3 dozen.