Line an 8×8-inch square baking pan with parchment paper, leaving a bit of an overhang on the sides. This makes it much easier to lift the bars out once they have set.
In a medium saucepan over low heat, combine the peanut butter, honey (or maple syrup), vanilla extract, and salt. Stir constantly until the mixture is completely smooth and well combined. Do not let it boil; you just want it melted and pourable.
Remove the saucepan from the heat. Add the rolled oats to the peanut butter mixture. Stir well with a spatula until every single oat is thoroughly coated in the peanut butter mixture.
Transfer the oat mixture into your prepared baking pan. Use the back of a spoon or a flat measuring cup to press the mixture down very firmly. Pressing hard ensures the bars stay together and don’t crumble when cut.
In a small microwave-safe bowl, combine the chocolate chips and coconut oil. Microwave in 30-second intervals, stirring in between, until the chocolate is smooth and glossy.
Pour the melted chocolate over the oat layer and spread it evenly with a spatula. Place the pan in the refrigerator for at least 2 hours, or until the chocolate and oats are completely firm. Slice into 12 bars and enjoy.