In a large mixer bowl, combine cake mix, flour, oats, melted butter, eggs, and vanilla. Beat on low speed for 1 minute or just until smooth. Stir in nuts and chocolate chunks.
Drop dough by rounded tablespoonfuls onto prepared sheets. Bake 10 to 15 minutes or until light golden. Cool 1 minute on wire racks or until firm on baking sheets then remove to racks and cool completely.