Peel the mango, then slice it off the pit, chop into cubes and set aside in a bowl.
Slice the passionfruit in half, scoop out the passionfruit pulp (including the seeds) and set aside in a bowl.
Place the mango mixture and passion fruit pulp into a small (2-3 quart pot) and turn the heat to medium.
Add the brown sugar to the pot and stir.
Add water to the pot and stir.
Once the ingredients reach a full rolling boil, turn the heat down to low.
Allow the contents of the pot to simmer on low heat until most of the liquid is gone (15-20 minutes).
Wash jars with warm, soapy water, then sterilize them.
Remove the pot from heat, place the cooked mango and passionfruit into a blender, and blend until achieving a uniform consistency.
Transfer the hot jam into warm sterilized jars, seal the jars, and store the jam in a cool dark place. Refrigerate after opening.