01 - In a small saucepan over medium heat, combine mashed banana, brown sugar, ground cinnamon, ground nutmeg, vanilla extract, and salt. Stir consistently until warmed through and sugar is dissolved, about 2 minutes.
02 - Add whole milk to the saucepan and whisk until hot but not boiling. Remove from heat.
03 - Using an immersion blender or standard blender, blend the banana milk mixture until completely smooth and frothy.
04 - Brew two shots of espresso or strong coffee and divide evenly between two large mugs.
05 - Pour the hot blended banana milk mixture over the espresso in each mug.
06 - Top with whipped cream, banana slices, and a sprinkle of cinnamon as desired. Serve immediately.