Add the biscuits in a food processor and blend until smooth.
Add the banana, peanut butter, vanilla and pinch of salt if you are using and blend until everything sticks together and forms a big ball.
Add the biscuit mixture in a bowl in the fridge and let it firm up for a bit, at least 30 minutes.
Shape the mixture into balls and place on a tray lined with parchment paper.
Crumble the chocolate into a bowl and place it over a pot with boiling water, creating a bain-marie (the bowl shouldn't be touching the hot water!). Wait for the chocolate to melt and remove from the heat.
Alternatively, melt the chocolate in a microwave. Add the chocolate in a bowl, cover with cling film and add in the microwave for 30 seconds at 800w. Remove, check if it has melted, if not add for additional 30 seconds. Be careful not to burn the chocolate.
Dip one by one the balls into the melted chocolate and stir around carefully until fully covered. Remove the ball from the melted chocolate with a fork or spoon and place on tray with a parchment paper.
Place the tray in the fridge until the chocolate sets and then store in a container in the fridge for up to 10 days.