Peel and core avocados and place them in a bowl.  Mash avocados well, getting out as many chunks as you can.

Melt the chocolate in a heatproof bowl over a pot of boiling water.

Whisk in the avocado and salt and scrape down sides with spatula until well combined.  It helps to drag the spatula on the bottom of the bowl to mash and incorporate any stubborn chunks of avocado and has a thick consistency.

Cover the bowl and refrigerate the mixture for about an hour, until it can be rolled into balls.

Place cocoa powder into a small bowl.  Use a melon baller or spoon to form the chilled chocolate avocado mixture into ¾” balls.  Roll them in your hands slightly to form them, and then roll each truffle in cocoa powder, making sure to cover each one.  Arrange them in a single layer on a serving plate or dish.  Refrigerate until ready to serve.