In a large mixing bowl, beat together butter and cream cheese until combined. Beat in the eggs and vanilla until fluffy. Mix in cake mix until well combined and stir in the chocolate chips.
Cover and chill for 30 minutes.
Line a baking sheet with parchment paper. Scoop dough into round balls (about 2 oz) and place onto the baking sheet.
Bake at 350 degrees for 10-12 minutes.
Remove from oven, allow to cool for a couple of minutes.
Recipe by Eleni Saltas at https://elenisaltas.com/2018/07/15/festive-blue-white-cookies/