Line a 9x9-inch baking pan with parchment paper, leaving some overhang for easy removal later.
In a mixing bowl, combine the peanut butter, coconut oil, honey (or maple syrup), and vanilla extract. Stir until smooth.
Add the rolled oats, salt, and cinnamon to the wet mixture. Mix thoroughly until cohesive.
Pour the oat mixture into the prepared baking pan. Press it down evenly using a spatula.
In a double boiler or microwave-safe bowl, melt the dark chocolate chips with 2 tablespoons of coconut oil until smooth.
Pour the melted chocolate over the pressed oat base and spread it evenly.
Refrigerate the baking pan for at least 2 hours to allow the squares to set fully.
Once set, use the parchment paper to lift the squares out of the pan and cut into squares or bars.