In a bowl whisk the heavy cream, vanilla, and powdered sugar using an electric mixer or by hand using a whisk until stiff peaks form. Then refrigerate until ready to use.
Brew the espresso (or coffee) according to the directions on the coffee maker.
Heat the milk in a small saucepan over medium heat, stirring constantly. Be careful not to scald or boil the milk.
Depending on the pastry, warm it in the oven at 350 °F (177 °C) if needed.
Place the chocolate syrup in a coffee mug. Stir in the espresso. Then stir in the heated milk. Top with whipped cream. Drizzle chocolate syrup over top.