Steamy Hot Chocolate

1 quart milk
1 cup semisweet chocolate chips
1/4 cup unsweetened cocoa powder
1 teaspoon pure vanilla extract
Pinch of salt
Whipped cream, for serving

In a medium saucepan over medium heat, combine milk, chocolate chips, and cocoa powder. Cook, whisking, until chocolate chips melt and cocoa powder dissolves. Stir in vanilla and salt. Remove from heat. Ladle into mugs and top with whipped cream and marshmallows.