Slice 3 medium bananas into small pieces and place them into a Ziploc freezer bag and into the freezer.

For the Greek yogurt, I used a cheesecloth to strain as much of the liquid from it that I could until it reached a thick, creamy consistency - much like cream cheese. This helps give the ice cream the creamy consistency that you would find in regular ice cream.

Line a small strainer with a cheese cloth & scoop desired amount of plain Greek yogurt into the cheese cloth.

Place the strainer over a bowl to hang - giving it room at the bottom for the yogurt to strain down. If your strainer is too big or you don't have a bowl to do this in - twist the top of the cheese cloth, place it over the lip of a mason jar and place a rubber band around the mason jar to secure it. Make sure it is hanging in the mason jar.

Cover and refrigerate overnight to strain. Or if you don't have the night to do this, simply pull the edges of the cheesecloth up over the Greek yogurt, twisting it closed to ensure nothing will accidentally squeeze out, and squeeze freely over a bowl or directly into your sink and down the drain.

Remove the bananas from the freezer and allow them to thaw slightly. While the bananas are thawing, scoop the "cream cheese" from the cheesecloth into a food processor or blender. Combine with the vanilla extract, sweetener (if any) and bananas. Process until it reaches a creamy consistency.

While you're waiting, prepare the PB2 by combining it with approximately 2/3 cup or more of water. If you do not use PB2, you can simply substitute it with 1/2 cup (or more, to your taste preference) of regular peanut butter, or any nut butter of your choice. Process until the peanut butter has fully mixed with the ice cream. Pour the ice cream into a freezer safe bowl (or ice cream container), fold in the chocolate chips and place into the freezer for a few hours. Remove, scoop, add your toppings of choice and enjoy!