Peel the sweet potato and cut it into small pieces.
Place the sweet potato pieces in a microwave-safe bowl. Add 3 tbsp of water, cover with a lid or plastic wrap (poke a few holes), and microwave for 5 minutes until soft.
In a cup, combine milk, heavy cream, and sugar (or honey). Microwave for 1 minute to warm it up.
Transfer the cooked sweet potato and the warm milk mix into a blender. Blend until smooth and creamy.
Pour the sweet potato latte into a cup and sprinkle a pinch of cinnamon powder on top.
If you want milk foam like in the photo, use an electric milk frother to whip warm milk and spoon it over the latte.