Preheat the oven to 190 degrees C. Sift together the flour, bicarbo soda, salt and cinnamon; stir in the oats and set aside. Grease baking trays.
In a large bowl cream together the butter, white sugar and brown sugar until light. Beat in the eggs one at a time then stir in the vanilla. Stir in the flour mixture alternately with the buttermilk. Fold in the raisins and walnuts. Drop by rounded spoonfuls onto the prepared baking trays.
Bake for 8 to 10 minutes in the preheated oven until lightly browned. Allow biscuits to cool on baking tray for 5 minutes before removing to a wire rack to cool completely.