In a medium bowl, mix together cocoa powder, sugar and salt.

In a second medium bowl, whisk together cornstarch and cream.

In a medium/large saucepan over medium heat milk until just nearly boiling. Remove from heat, pouring roughly half of the milk into cream mixture, whisking as you pour. Add dry ingredients, whisking well.

Pour cocoa mixture into remaining milk. Cook 1 minute over medium heat, whisking constantly until thick and bubbly. Remove from heat, add milk chocolate pieces and vanilla. Whisk until smooth.

Transfer to serving dishes or a large bowl. Serve warm or cover and chill for a minimum of 30 minutes.

Serve with optional sweetened whipped cream.