German Chocolate Cake

Today is Nate's birthday, and german chocolate cake has always been his absolute favorite birthday cake, so he's getting it!  This is my first time making it, and I got my recipe from All Recipes.

1 (18.25 ounce) package Pillsbury® German Chocolate Cake
1 cup water
3 eggs plus
1 egg yolk
1/2 cup Crisco® Pure Vegetable Oil
1 (14 ounce) can EAGLE BRAND® Sweetened Condensed Milk
3 tablespoons butter or margarine
1/3 cup chopped pecans
1/3 cup flaked coconut
1 teaspoon vanilla extract

1.Preheat oven to 350 degrees F. In large bowl, combine cake mix, water, 3 eggs, oil and 1/3 cup sweetened condensed milk. Beat on low speed until moistened, then beat on high speed 2 minutes.

2.Pour into well-greased and floured 13 x 9-inch baking pan. Bake 40 to 45 minutes or until wooden toothpick inserted near center comes out clean.

3.In small saucepan, combine remaining sweetened condensed milk, egg yolk and butter. Over medium heat, cook and stir until thickened, about 6 minutes. Add pecans, coconut and vanilla; spread over warm cake. Store leftovers covered in refrigerator.