Combine the cocoa and sugar in a saucepan.
Stir in the boiling water.
Bring mixture to an soft boil while stirring.
Simmer for about 2 minutes careful it doesn't scorch.
Stir in 3 1/2 cups of milk and heat until just before boiling.
Remove from heat and add vanilla and peppermint bark sauce.
Pour into four mugs.
Add the cream to the mugs of cocoa to cool it to drinking temperature.
Garnish with marshmallows and whipped cream.
ENJOY!