In a large saucepan over low heat, melt butter; remove from heat; set aside.
In your food processor or food blender, puree the avocado until a smooth consistency. If you add a little of the melted butter to the avocado, it helps in the process. Be sure there are no chunks of avocado left.
Add the avocado puree, vanilla extract, cocoa, and powdered sugar into the saucepan with the remaining melted butter. Mix until well combined. Place the chocolate mixture into the refrigerator until it hardens.
When chocolate mixture has hardened, remove from refrigerator. Line a sheet pan or cookie sheet with waxed paper or parchment. Using a cold metal teaspoon, melon baller, or a mini ice cream scoop and your hands, roll the chocolate into small balls about 3/4-inch diameter and arrange them on the sheet pan. If the mixture gets too soft to mold easily, put it back in the freezer for a few minutes. Place the cookie sheet of chocolate balls in the refrigerator until firm.
Once the truffles have hardened, remove from the refrigerator and shape into balls by rolling between the palms of your hands. Roll in powdered sugar to coat the outside.
Place the finished truffles in the refrigerator until they are set. They should be stored in a covered container in the refrigerator until ready to serve. Bring to room temperature when ready to serve.
* If an avocado is ripe, it will yield to a gentle pressure.
Avocado Chocolate Truffle Recipe: https://whatscookingamerica.net/candy/avocadochoctruffles.htm