Start by brewing 2 cups of strong hot coffee, or pull 4 shots of espresso if you have a machine. I always go one scoop heavier than my usual morning brew because the sweetened milk softens the coffee flavor a lot. Keep it covered or in a warm carafe so it does not cool down while you handle the milk.
Pour the almond milk into a small saucepan, then add the brown sugar and ground cinnamon. Set it over medium heat and stir gently until the sugar dissolves completely and no grainy bits are left at the bottom. Bring it just to the edge of a boil, then take it off the heat right away.
While the mixture is still hot, slide the milk frother in and run it for about thirty seconds. Move the frother up and down slightly so you pull air through the whole pan instead of just the surface. You want a thick, glossy foam that holds its shape when you tilt the pan.
Divide the hot coffee or espresso evenly between two warm mugs, filling each about halfway. I rinse my mugs with hot water first, because cold ceramic drops the temperature fast and ruins the foam. Leave enough room on top for the milk, otherwise you will lose the best part over the rim.
Slowly pour the frothed almond milk over the coffee, holding back the foam with a spoon at first. Once the liquid is in, spoon the reserved foam right on top so it sits in a soft, rounded cap. Pour from a low height, since dropping the milk from too high breaks the bubbles instantly.
Dust a little extra cinnamon over the foam and slide in a cinnamon stick if you have one. Give it about thirty seconds to settle so the layers relax and the drink stops steaming aggressively. Serve it right away, while the foam is still tall and the coffee is still properly hot.