Put all ingredients except the shortening in a large bowl; use a spoon to mix until uniform. Cut in shortening using either a pastry blender or your fingertips until mixture looks like chocolate cornmeal. Seal tightly in a plastic bag or jar, label and store at room temperature.
To Use: Put 2 eggs and 1 teaspoon vanilla or orange extract in a mixing bowl; beat slightly. Stir in 4 tablespoons melted butter or margarine which has been cooled. Lightly spoon 2 cupsof the mix into the mixing bowl; do not pack the mix when measuring. Beat well with a spoon to make a somewhat smooth batter; stir in 1/2 cup chopped nuts, if desired. Spread into a greased and floured 8 x 8 x 2 inch pan. Bake in a preheated 350 degree F. oven for 30 to 35 minutes or until a knife inserted in the center comes out clean. Cool in pan then cut into squares.
