Polar Express Hot Chocolate

If you're looking for the chocolatiest, richest, most decadent hot chocolate ever, look no more.  This is it!  You have to try this.  It's insanely good!  Of course, you can top it off with a dollop of whipped topping to make it even richer, if that's possible. :)  Enjoy!
-1 1/2 cups heavy cream
-1 (14 oz) can sweetened condensed milk
-2 cups semi sweet chocolate chips
-6 cups milk
-1 tsp vanilla extract
Mix everything in a large pot over medium heat.  Cook until simmering and chocolate is melted.  Pour hot into mugs.  Top with a dollop of whipped topping, if desired.  Enjoy!