butter until everything is evenly combined and the mixture looks like thick, slightly crumbly dough. It should hold together when pressed between your fingers; if it seems too dry and sandy, add another tablespoon or two of peanut butter and mix again.
Transfer the graham cracker–peanut butter mixture to the prepared glass baking dish. Use clean hands or the back of a spoon to press it firmly and evenly into the bottom of the dish, creating a dense, compact base. Take a moment to really pack it down so the bars hold together when sliced.
Pour the chocolate chips into a microwave-safe bowl. Microwave on high in 20–30 second bursts, stirring well after each burst, until the chocolate is completely smooth and glossy. This usually takes about 1–2 minutes total, depending on your microwave. Do not overheat; stop as soon
