In a medium sized bowl take melted butter, 1 cup peanut butter, powdered sugar and graham cracker crumbs and mix together. Mix fully and make a smooth mixture.
Form the Bars
In a greased or parchment paper-lined 9x9-inch pan, press the peanut butter mixture evenly.
Make the Chocolate Topping
In a microwave-safe bowl, mix the chocolate chips and 1/4 cup of peanut butter and place in the microwave. Microwave for 20 seconds on high, then take it out and give it a good stir. Repeat until fully melted and smooth.
Add the Topping
After the peanut butter mixture has been cooled and set, pour the melted chocolate mixture on top, smoothing it out to cover completely.
Chill
Refrigerate the pan for 1-2 hours, or until the bars are firm and set.
Serve
After chilling, the bars are cut into squares and served. You can store any leftovers in the refrigerator for as long as a week.