Preheat the oven to 375 degrees Fahrenheit. Grease a baking sheet, and set aside.
Slightly thaw the puff pastry until it is easy to work with but still cold. Spread it out into a large triangle.
1 sheet puff pastry
Arrange the chocolate bar, ½ cup peanut butter, and 5 peanut butter cookies in the center of the dough.
1 (4-ounce) chocolate bar, 1/2 cup peanut butter + more for drizzling, 8 peanut butter sandwich cookies
Slice 1-inch sections of the dough from the center out. Carefully cut off the top two sections and the bottom two sections of the dough.
Fold the top piece down over the center. Begin braiding by folding one piece down at a time, alternating sides, and overlapping the dough.
Tuck the bottom piece under the last fold.
In a small bowl, whisk the egg. Use a pastry brush to brush the egg over the top of the puff pastry braid.
1 large egg
Carefully transfer the braid to the prepared baking sheet.
Bake 15-20 minutes or until fluffy and golden brown.
Crush the remaining peanut butter cookies into pieces, and sprinkle them on top along with a drizzle of peanut butter, if desired.
Serve warm or at room temperature.
Store at room temperature for up to 1 day or in the fridge for up to 5 days.