Start by lining a large baking tray or cutting board with parchment paper. This will make cleanup super easy!
In a microwave-safe bowl, melt your peanut butter and white chocolate chips on a low or defrost setting. Stir the mixture often until it's smooth and creamy. Once melted, transfer the mixture into a piping bag and let it cool for about 5 minutes—just enough time for it to be easy to handle but not too thick.
Take your fudge striped cookies and place them striped side down on the parchment paper. These will be the base of your Pilgrim Hats.
Snip the tip off your piping bag and pipe a small circle of the melted peanut butter-white chocolate mixture into the center of each cookie. The circle should be about the size of a Reese’s miniature cup—this will act as the "glue" for your Pilgrim Hat.
Place a Reese’s miniature cup upside down (large side down) on top of the piped mixture, pressing gently so that the peanut butter mixture forms a "hat band" around the base of the cup.
For the finishing touch, press a mini M&M onto the hat band to create a cute little buckle. How adorable is that?!
Now, let your Pilgrim Hats set completely. You can pop them into the fridge for 10-15 minutes to speed up the process. Once the peanut butter and white chocolate mixture hardens, these hats will hold their shape perfectly.