You’ll want a mixer for this one. Cream together the shortening, butter, both sugars, vanilla, and eggs. Then add the other ingredients.
When you get to the cornflakes, you probably want to switch to hand-stirring the rest just to avoid over-crunching the “fun stuff.”
Drop by spoonfuls onto a cookie sheet. Bake at 350 for 15 minutes. Immediately remove the cookies from the sheet when they come out if you want gooey cookies. Let them rest a minute or a two if you like them crispier. Enjoy!