In a medium saucepan, combine 2 cups of whole milk and 1 cup of heavy cream over medium-low heat. Stir gently while warming until it starts to steam, about 3 to 5 minutes.

Once warm, add ⅓ cup of unsweetened cocoa powder and ¼ cup of granulated sugar. Whisk vigorously until fully dissolved, about 1 to 2 minutes.

Stir in 1 teaspoon of pure vanilla extract and simmer gently for about 3 minutes.

Add ½ cup of semi-sweet chocolate chips, whisking continuously until melted, about 1 to 2 minutes.

If desired, add a pinch of salt and stir well for 1 minute.

Pour into mugs, add toppings like marshmallows or caramel, and enjoy!