Prepare your pan: Line an 8x8-inch baking dish with parchment paper, leaving some overhang for easy removal later.
Mix the base: In a large mixing bowl, combine the melted butter and creamy peanut butter. Stir until smooth, then gradually mix in the powdered sugar and graham cracker crumbs until fully incorporated.
Press into the pan: Transfer the peanut butter mixture to the lined baking dish. Use a spatula to press it down firmly and evenly.
Melt the chocolate: In a microwave-safe bowl, melt the semi-sweet chocolate chips and coconut oil in 30-second intervals, stirring each time until smooth.
Spread the chocolate: Once the chocolate is fully melted, pour it over the peanut butter layer and use a spatula to spread it evenly.
Chill to set: Place the dish in the refrigerator and let it chill for at least 2 hours to fully set before cutting into squares.
Serve and enjoy: Lift the bars out of the dish using the parchment paper, slice into squares, and enjoy your homemade treats!