Ho Ho Cake

1 (9 ounce) package chocolate cake mix

5 tablespoons all-purpose flour

1 1/4 cups milk

1 cup white sugar

1/2 cup margarine

1 cup shortening

1/2 cup margarine

1 teaspoon vanilla extract

1 egg

1 1/2 teaspoons hot water

3 (1 ounce) squares unsweetened chocolate, melted

1 3/4 cups confectioners' sugar

Directions

1. Prepare and bake cake as directed on the package for a 9 x 13 inch pan. Cool completely.
2. Combine flour and milk in saucepan. Cook, stirring constantly, until thick. Cool completely. Cream 1 cup sugar, 1/2 cup margarine, and shortening. Add cooled milk mixture, and beat well. Spread over cake. Refrigerate.
3. In a small bowl, beat egg. Stir in vanilla, melted chocolate, hot water, confectioner's sugar, and 1/2 cup margarine. Pour over second layer. Refrigerate