Halve the vanilla pod lengthways and scrape out the pulp.
Combine the milk, vanilla pulp, maple syrup, Nutella, and a pinch of cinnamon in a saucepan. Heat over medium heat for 5 minutes, stirring occasionally, until steaming (about 65 °C / 150 °F).
In a bowl, whip the cream with the cream stabilizer and the remaining cinnamon until stiff peaks form (2-3 minutes).
Froth the hot milk by whisking vigorously for 1-2 minutes until foamy.
Pour the hot milk into four glasses.
Top each glass with the whipped cinnamon cream and chocolate flakes, then serve immediately.