Cut open the bananas lengthwise but do not slice all the way through. Place the bananas on the foil. Wrap the bananas in the foil, leaving the incision free. Stuff the chocolate into the bananas, top with the granola.
To grill the bananas
Charcoal/gas/electric grill: Grill the bananas over/on a medium heat (approx. 200 °C for approx. 12 mins.