Add peanut butter and graham cracker crumbs to a mixing bowl. Stir together with a wooden spoon until well blended.
Microwave butter in a small bowl until melted. Pour butter and vanilla into the peanut butter mixture and stir to combine.
Add powdered sugar and stir until the powdered sugar is fully incorporated into the peanut butter.
Take a heaping tablespoon of the peanut butter mixture and shape it into a disk about the size of a silver dollar. Repeat until you have 12 disks.
Melt chocolate in a microwave-safe bowl. Heat for 30 seconds and then stir. Repeat until the chocolate is smooth.
Place foil, paper, or silicone baking cups into miniature muffin tin cups. Pour 1 tablespoon of chocolate into each cup. Then add a peanut butter disk on top of the chocolate. Top with more chocolate to cover the peanut butter and fill the cup. (Reheat chocolate as needed to keep it melted.)
Refrigerate candies for 20 minutes or until firm. Keep refrigerated or in a cool area until ready to serve.
You can make graham cracker crumbs by placing whole graham crackers into a food processor and pulsing OR into a plastic food storage bag and smashing with a rolling pin.