In a medium mixing bowl, mash the banana until smooth using a fork or potato masher.
Add the Greek yogurt, vanilla extract, peanut butter, and chopped peanuts if using. Stir until the mixture is smooth and fully combined.
Place the dark chocolate chips and coconut oil into a microwave-safe bowl.
Microwave in 30-second intervals, stirring after each interval until completely melted. Alternatively, melt the chocolate using a double boiler.
Spoon approximately 1 teaspoon of melted chocolate into each cavity of a silicone ice cube tray or silicone mold.
Use the back of a spoon to gently spread the chocolate up the sides of each mold, creating a thin chocolate shell.
Freeze the tray for about 5 minutes until the chocolate has hardened.
Fill each cavity with approximately 2 tablespoons of the peanut butter yogurt mixture, depending on the size of your mold.
Cover each bite with a thin layer of the remaining melted chocolate, smoothing gently with a spoon if needed.
Freeze the Chocolate Peanut Butter Frozen Greek Yogurt Bites for about 2 hours or until completely firm.
Remove from the molds and enjoy after letting them sit at room temperature for 2 to 5 minutes for the best creamy texture.