Chocolate Sandwich Cookies

1 cup shortening
2 cups sugar
2 eggs
1 cup sour cream -- (8 oz)
1 cup hot brewed coffee
1 teaspoon vanilla extract
4 cups all-purpose flour
3/4 cup baking cocoa
2 teaspoons baking soda
1/2 teaspoon baking powder

FILLING:

3 tablespoons all-purpose flour
1 cup milk
1/2 cup butter or margarine -- softened
1/4 cup shortening
1 cup confectioner's sugar
1 teaspoon vanilla extract
1/4 teaspoon salt

In a mixing bowl, cream shortening and sugar. Add eggs, one at a time,
beating well after each addition. Beat in sour cream, coffee and vanilla.
Combine the dry ingredients; gradually add to the creamed mixture. Drop by
tablespoonfuls 2 in. apart onto greased baking sheets. Bake at 350° for 9-11
minutes or until firm to touch. Remove to wire racks to cool. In a
saucepan, combine flour and milk until smooth. Bring to a boil; cook and
stir for 2 minutes or until thickened. Cool to room temperature. In a
mixing bowl, combine remaining filling ingredients; add the milk mixture and
mix well. Spread 2 teaspoonfuls of filling on the bottom of half the
cookies; top with remaining cookies.