In a small bowl, whisk together the miso and 1 tbsp hot water until a smooth paste forms. Set aside.
To a small saucepan, add the brown sugar and ½ cup of water. Place over medium heat and stir frequently until the sugar has dissolved. Bring to a simmer.
Once simmering, turn off the heat and whisk in the miso paste until it has dissolved. It's ok if there are a few small chunks.
Strain into an airtight container using a fine mesh strainer. Cool completely before using.
To make the latte, add the milk to a glass and fill with ice. Combine the brown sugar miso syrup and espresso then pour it over the milk. Stir and enjoy!
