German Chocolate Cake Topping

This topping is so good.  It's from my mother-in-law Nanette.  It's always requested for birthdays in our family.  This was for Aron's bday on New Year's Day.  My side of the family likes to add coconut and chocolate chips to the cake batter before baking.  Yum:)

German Chocolate Cake Topping

Ingredients

• 1 pkg German Chocolate Cake Mix, baked (may add coconut and chocolate chips to batter)
• 12 oz evaporated milk (I used fat free)
• 1 block butter
• 3/4 cup white sugar
• 3 egg yolks
• 3/4 tsp vanilla
• 1 1/2 cup shredded coconut

Instructions

Mix all ingredients in a pot over medium heat.  Stir constantly.  Bring to boil then take off heat and add coconut.  Let cool before spreading over cake.  It's enough to do a 2 layer cake.