All-Purpose Cake Mix (From Make-A-Mix-Cookery)

10 cups all-purpose flour
6 1/4 cups sugar
1 cup cornstarch
5 Tbsp baking powder
1 Tbsp salt
(1 1/4 cups whole egg powder, opt.)
5/8 cups dry milk
2 1/2 cups shortening

In a large sifter, combine flour, sugar, cornstarch, baking powder, and salt (and egg powder).  Sift into a large bowl.  Use a pastry blender to cut in shortening until mixture resembles cornmeal in texture.  Store in an airtight container.  Label and use within 10-12 weeks.