Chocolate Cake Filling

Why I Love This Recipe
I like to use this as a filling for both chocolate and yellow cakes. It's also delicious as a frosting.
Ingredients You'll Need
3 oz unsweetened chocolate, chopped
¾ cup sugar
¼ cup milk
1 cup heavy cream
5 egg yolks
2 tsp cornstarch
small pinch of salt
dash of vanilla
Directions
Heat and stir until dissolved in a heavy sauce pan:
3 oz unsweetened chocolate, chopped
¾ cup sugar
¼ cup milk
1 cup heavy cream
In a bowl beat until thick:
5 egg yolks
2 tsp cornstarch
small pinch of salt
dash of vanilla
Stir the egg yolk mixture into the the chocolate mixture and continue to cook over low heat, stirring constantly until thickened, simmer for a minute or two. Take off of heat, and let cool, stirring occasionally to prevent a skin from forming. When it is cool, pour into a mixing bowl and beat in:
1 cup unsalted butter
Beat until it's well mixed.