In a small bowl, beat together the flour, shortening and oil with a hand mixer. The mixture will be thick.
Store in an airtight container in the refrigerator for up to 4 months.
*We let our cakes cool in the pan only 10 minutes (unless the recipe otherwise states something else) and then turn them onto a wire rack to cool completely. Sometimes if you leave a cake in the pan too long after baking, it can stick.**The calories shown are based on the 1 tablespoon of pan grease. (You're not actually eating the pan grease, but it will get in your cake. :) ) Since different brands of ingredients have different nutritional information, the calories shown are just an estimate.