1. Line a pan with foil or parchment paper. Make sure there's more than enough space so your bars will be easy to remove later.
2. Mix the melted butter and peanut butter in a large bowl until well combined. Add the graham cracker crumbs, 1 cup at a time, and mix well.
3. Scoop the mixture into the baking pan and firmly press it down into one even layer. Leave it to chill for at least ten
minutes in the freezer.
4. To make the topping, melt for 20 to 30 seconds, then reset and stir, and melt again until it’s completely liquid. Continue
until it's mixed thoroughly.
5. Remove the pan from the freezer and pour the chocolate mixture over to create an even layer.
6. Cover and refrigerate for at least 1.5 hours or until the bars are firm and the chocolate topping is set.
7. Once firm, lift them out of the pan using the overhang from the foil or parchment paper. Slice and devour.