Cream-Filled Cupcakes

3 cups all-purpose flour
2 cups sugar
1/3 cup baking cocoa
2 tsp. baking soda
 1 tsp. salt
2 eggs
1 cup milk
 1 cup vegetable oil
1 cup water
1 tsp. vanilla extract
Filling:
1/4 cup butter or margarine, softened
1/4 cup shortening
 2 cups confectioners' sugar
3 Tbsp. milk
1 tsp. vanilla extract

Pinch salt
Chocolate frosting

In a mixing bowl, combine the first five ingredients.  Add eggs, milk, oil, water and vanilla.  Beat until smooth, about 2 minutes.  Fill paper-lined muffin cups half full.  Bake at 375 degrees for 15-20 minutes or until a toothpick inserted near the center comes out clean  Remove from pans to wire racks to cool completely.  In a mixing bowl, combine butter, shortening, confectioners' sugar, milk, vanilla and salt; beat until fluffy, about 5 minutes.  Insert a very small tip into a pastry or plastic bag; fill with cream filling.  Push the tip through the bottom of paper liner to fill each cupcake.  Frost tops with chocolate frosting. 
Yield:  3 dozen.