In a medium saucepan, whisk together the cocoa powder, sugar, and salt until well combined.
Add 1/4 cup of the milk to the cocoa mixture and whisk until it forms a smooth paste with no lumps.
Pour in the remaining milk and add the chocolate chips, then heat over medium heat, whisking frequently.
Continue whisking until the chocolate chips are completely melted and the mixture is steaming hot but not boiling, about 4-5 minutes.
Remove from heat and stir in the vanilla extract.
Pour into two mugs, top with whipped cream, dust with cocoa powder, and serve immediately.