German chocolate cake squares

1. Make cake: Preheat oven to 350°F. Butter 13x9x2-inch glass baking dish. Bring water to simmer in small saucepan. Reduce heat to low. Add chopped chocolate; whisk until smooth. Cool. Sift flour, baking soda and salt into medium bowl. Using electric mixer, beat sugar and butter in large bowl until blended. Beat in yolks 1 at a time. Beat in chocolate mixture and vanilla. Beat in dry ingredients alternately with buttermilk. Using clean dry beaters, beat whites in another large bowl until stiff but not dry. Fold into batter in 2 additions. Pour batter into prepared dish. Sprinkle with chocolate chips. Bake until tester inserted into center comes out clean, about 1 hour. Cool cake in pan on rack. Make frosting: Combine first 5 ingredients in heavy large saucepan. Whisk over medium-high heat until mixture simmers, thickens and leaves path on back of spoon when finger is drawn across, about 18 minutes. Mix in coconut and pecans. Spread warm frosting over cake. Immediately sprinkle 1/4 cup chocolate chips over. Let stand until frosting sets, about 2 hours. Cut cake into squares and serve.