In a medium bowl, beat together cream cheese and butter until smooth. Mix in confectioners' sugar, brown sugar and vanilla. Stir in chocolate chips. Cover, and chill in the refrigerator for 2 hours if you want it more firm.
Shape chilled cream cheese mixture into a ball. or place in a bowl and use as a dip.
Roll the cheese ball in finely chopped pecans before serving (optional). Serve with graham crackers (stick graham crackers work the best, but are hard to find if it isn't holiday time).