Step 2) Cream shortening, oil, sugar and eggs in a large mixing bowl. Add food coloring, buttermilk, vanilla, flour, cocoa powder and salt. Mix well.
Step 3) Dissolve baking soda in the vinegar; add to the cake batter. Beat thoroughly. Grease and flour two 8 or 9-inch round baking pans, OR one 13 x 9-inch pan. Pour batter into prepared pan(s).
Step 4) Bake for 35 to 40 minutes or until toothpick inserted in center comes out clean. Cool 10 minutes. Remove from pans. Cool completely. Frost.
Frosting Directions:
Step 1) Heat milk and flour in small saucepan over medium heat until thickened, stirring constantly. Remove from heat and cover with plastic wrap placed directly on the milk (to prevent skin formation). Cool completely at room temperature.
Step 2) Cream butter and sugar in medium mixing bowl using electric mixer. Add vanilla and food coloring (if desired) and blend well. Beat in cooled milk mixture until light and fluffy and of spreading consistency. (Note: if frosting is too thin, chill in refrigerator for 5 to 10 minutes and beat again).
Step 3) Store iced cake in the refrigerator.
TIP: For a valentine cake, use heart shaped layer cake pans.