Mix cake mix, butter, egg and vanilla extract. Add in cream cheese and beat until combined.
Stir in Oreo chunks.
Refrigerate dough 30 minutes to 1 hour. Remove and scoop or roll into 1 inch ball shaped cookies.
Bake at 350 degrees for 8 - 9 minutes. Let rest on baking sheet for 2 to 3 minutes. Remove to completely cool on baking rack. Store in airtight container.