In a large bowl, stir together the cake mix, oats and baking powder. Make a well in the centre and add the eggs and margarine; mix until well blended. Stir in the chocolate chips and walnuts. Drop by rounded spoonfuls onto an ungreased baking tray.
Bake for 8 to 10 minutes in the preheated oven. Allow biscuits to cool on baking tray for 5 minutes before removing to a wire rack to cool completely.