german chocolate cupcakes1 box Devil’s Food Cake Mix  3 eggs  ½ cup oil  1 teaspoon vanilla extract  ¾ cup buttermilk  1 cup sour cream  German Chocolate Frosting:  1 cup evaporated milk  1 cup sugar  3 egg yolk, lightly beaten  1/2 cup butter  1 ½ teaspoon vanilla extract  1 ½ cup chopped pecans  1 ½ cup flaked coconut