You can cream a cup of fat into a cup of sugar and two cups of flour, and the resulting dough can be baked into a well-shaped cookie. If you try to substitute a cup of oil for the fat, you will be disappointed with the greasy flat "cookie." Foods that are fried in unrefined oil are also frequently greasy. The food industry knows that cookies and crackers, as well as cakes, pastries, and donuts have to be made with a fat at least as firm as a soft fat like lard or palm oil, so the industry changes the very liquid oils, such as soybean, corn, canola, cottonseed, and sometimes peanut oils and safflower oils, into fats by [partial hydrogenation].