Heat oven to 350°F. Grease 3 (9-inch) round cake pans with shortening; lightly flour. In 1-quart saucepan, melt chocolate with water over low heat, stirring frequently. Cool.
In large bowl, beat 2 cups sugar and 1 cup butter with electric mixer on medium speed until light and fluffy, scraping bowl occasionally. Add 4 eggs, one at a time, beating and scraping well after each addition. Beat in chocolate mixture. On low speed, beat in remaining cake ingredients until well blended, scraping bowl occasionally. Pour batter evenly into pans.
Bake 35 to 45 minutes or until toothpick inserted in center comes out clean. Cool in pans 5 minutes. Remove from pans; place on wire racks. Cool completely, about 1 hour.
In 2-quart saucepan, cook 1 cup sugar, the evaporated milk, 1/2 cup butter and 3 eggs over medium heat, stirring constantly, until mixture begins to bubble. Remove saucepan from heat. Stir in coconut, pecans and 1 teaspoon vanilla. Cool completely, about 30 minutes.
Place 1 cake layer, top side down, on serving plate. Spread with 1/3 of frosting. Repeat with remaining cake layers and frosting, ending with frosting.