Place the chocolate in a medium mixing bowl and set aside.
In a medium saucepan combine the milk, heavy cream, and butter and cook over medium high heat until the mixture just comes to a boil. Remove from the heat and pour over the chocolate. Allow mixture to sit, undisturbed, for 1 to 2 minutes. Whisk mixture until all chocolate melts and the sauce is very smooth. Whisk in vanilla and serve immediately, or place in a heat-proof bowl and cover the surface with plastic wrap to prevent a skin from forming.
When the mixture is cool, refrigerate for up to 3 weeks. Mixture may be reheated gently as needed, or microwaved for 30-second intervals until the sauce melts.
![]("/food/images/spacers/spacer.gif"){kind=spacer}
