Step 1: In a medium-sized bowl, combine graham cracker crumbs and powdered sugar until well blended. Set aside.
Step 2: In a microwave-safe dish, combine peanut butter and 6 tablespoons butter. Cook in the microwave in 15-second increments, stirring in between, until melted and combined. Pour over the graham crackers mixture. Continue to stir until well combined. Set aside.
Step 3: In a microwave-safe dish, combine half of the chocolate chips (6 ounces) with 2 tablespoons of butter. Cook in the microwave in 15-second increments, stirring in between, until melted and combined. Set aside.
Step 4: Place cupcake liners in a cupcake tin.
Step 5: Using a paintbrush or pastry brush, paint each cupcake liner with melted chocolate. If using full-size cupcake liners, paint about one-third of the way up each cup. If using mini cupcake liners, paint halfway up each cup. Be sure to evenly coat the bottom and sides. You don't need to paint the chocolate super thick, just enough so you don't see any of the liner underneath. Place in the refrigerator to cool for about 5 minutes, or until chocolate hardens.
Step 6: Press about 1 tablespoon graham cracker mixture in each full-size cup (about 1 teaspoon for mini cups), making sure the top is somewhat flat. It doesn't need to be perfect; just make sure you don't go above where you painted the chocolate on the cup. Set aside.
Step 7: Add the remaining chocolate chips to the remaining melted chocolate in the microwave-safe dish. Melt with remaining 2 tablespoons butter, stirring every 15 seconds.Spoon a little chocolate over each peanut butter cup until the peanut butter filling is completely covered. You can lightly shake or tap the cupcake pan to even out the chocolate over the filling. You want the top of the peanut butter cups to look completely flat. Step 8: Place in the refrigerator or cool area until chocolate hardens, about 20 minutes, or until the chocolate is no longer shiny, then serve!
