Pull a double shot of espresso or brew about 2 fl oz of very strong coffee. Keep it piping hot and set aside in your serving mug.
Spoon the Nutella into the hot espresso. Use a small whisk or spoon to vigorously stir until the spread has fully melted and the espresso turns shiny and smooth (about 20–30 seconds).
Warm the milk in a small saucepan over medium-low heat until it steams and tiny bubbles form at the edges (do not boil). Stir in a pinch of ground cinnamon while heating to infuse the flavor.
Froth the warmed milk with a handheld frother, French press, or by shaking vigorously in a lidded jar for 20–30 seconds until light and slightly foamy.
Pour the milk into the mug over the Nutella-coffee mixture, holding back the foam with a spoon. Finish by spooning the foam on top, then add a generous dollop of whipped cream.
Dust the top with a little extra cinnamon or cocoa if desired and serve immediately while hot.