Preheat oven to 350 degrees.
Sift together flour, baking soda, and salt; stir in oats and cornflakes. Set aside.
Cream butter and sugars. Add egg and vanilla, then oil. Mix well. Add flour mixture; mix well.
Drop by spoonfuls onto ungreased cookie sheet.
Bake 10 to 12 minutes.
Recipe submitted by Joyce on 4/12/00