Add the cream to a small saucepan and set to a medium-low heat. Stir frequently until the cream starts to steam (do not let it boil). Remove from heat.
Add the cocoa powder, sugar, and coffee into the cream until smooth. Add the vanilla extract last. Allow the mixture to cool to desired consistency. Ideally, it should be spreadable.
For a warm mocha latte, steam milk first and have it set aside until ready to use.
Prepare the espresso and pour into your server or mug immediately. Add the chocolate ganache to the espresso and stir vigorously until the chocolate is totally dissolved.
If making an iced mocha latte, pour desired milk over the espresso and chocolate mixture and stir. Follow it up with a couple of ice cubes and whipped cream as a topper.
For a warm mocha, pour the steamed milk over the chocolate and espresso mixture and stir gently. Add whipped cream and a cocoa powder dusting over the top for garnish.