In a mixing bowl, combine the peanut butter, powdered sugar, and vanilla extract. Mix until smooth and well combined.
Add the graham cracker crumbs to the peanut butter mixture and stir until fully incorporated.
Line an 8x8-inch baking dish with parchment paper, leaving some overhang for easy removal.
Press the peanut butter mixture evenly into the bottom of the prepared baking dish.
In a microwave-safe bowl, combine the chocolate chips and coconut oil. Microwave in 30-second intervals, stirring in between, until melted and smooth.
Pour the melted chocolate over the peanut butter layer and spread evenly.
Refrigerate for at least 2 hours or until the chocolate is set.
Once set, lift the bars out of the dish using the parchment paper overhang and cut into squares.