Peel and slice ripe bananas into 1/4 inch rounds and place them on a cookie sheet.
Freeze the banana slices on the cookie sheet for at least 1 hour.
Melt the coconut oil, and mix in the cocoa powder, sugar, and salt until it's well combined.
Place a piece of parchment paper on another cookie sheet next to your prepared chocolate coating mixture.
Take the frozen bananas out of the freezer.
Quickly pick them up one piece at a time with a fork and dip them in the chocolate. Place them on the prepared parchment paper.
Repeat this with each slice until they have all been dipped.
Put them back in the freezer for at least 1/2 hour to refreeze them.
Notes
You must freeze the bananas before dipping or the chocolate coating will not stick to them as well. The chocolate will harden faster on the frozen bananas, making them look less messy.
If you want thicker chocolate, you can double-dip the bananas.
If you want nuts, sprinkles, kosher salt, etc. to stick to your chocolate-dipped bananas, sprinkle them on immediately after dipping. The chocolate will harden fast.
Don't overheat the coconut oil when you melt it. It just needs to be warm enough to stay in liquid form, you don't want it so hot that it melts the bananas.
Refreeze before bagging or stacking them in a container.