Add all ingredients to the blender and blend until a smooth paste forms.
Shape the chocolate truffles using about 1 tsp of the mixture per truffle.
Coat them with cocoa powder.
Serve right away or store them in the fridge.
Notes
The rum is optional and can be left out for a kid-friendly version. Store the truffles chilled in an airtight container in the fridge and serve cold for the best texture.