In a mixing bowl, combine the Greek yogurt, peanut butter, honey, and vanilla extract. Stir until the mixture is smooth and well combined.
If desired, fold in the mini chocolate chips and chopped peanuts for added texture and flavor.
Line an 8x8-inch baking dish with parchment paper, leaving some overhang for easy removal.
Pour the yogurt mixture into the prepared baking dish and spread it evenly with a spatula.
Freeze for at least 4 hours or until firm.
Once frozen, lift the bars out of the dish using the parchment paper and cut into squares or rectangles.
Serve immediately or store the bars in an airtight container in the freezer for up to 2 weeks.