Combine brown sugar, 2/3 cup shortening, water, and 1 teaspoon vanilla in large bowl. Beat until well blended. Beat eggs into creamed mixture.
In another bowl, combine flour, cocoa, salt, and baking soda. Mix this mixture into creamed mixture until just blended. Stir in chocolate chips.
Drop rounded tablespoonfuls of dough onto ungreased baking sheet about 2 inches apart. Place cookie sheet in the middle of the oven. Bake at 375 degrees F (190 degrees C) for 7 to 9 minutes, or until cookies are set. Do not over bake. Cool for 2 minutes on baking sheet. Remove cookies to wire rack to cool completely.
To Make Frosting: Begin by combining evaporated milk, white sugar, 1/4 cup shortening, and egg yolks in medium saucepan. Stir over medium heat until thickened. Remove pan from heat. Stir 1/2 teaspoon vanilla, pecans, and coconut into the warm mixture. Cool completely, and frost cooled cookies.