In a microwave, melt butter and chocolate chips for 1:30. Let sit 1 minute, then whisk gently. Reheat in 20-30 second increments until mixture is smooth. Whisk until well combined.
Cool butter mixture for 10 minutes on countertop, whisking once or twice. Stir in wafer crumbs and pecans.
Transfer to a parchment lined 8" square pan. Cover and refrigerate for 2 hours or until firm.
Lift cookies out of pan & cut into squares, 6 rows x 5 rows. Serve & enjoy!
Notes
Store leftovers in an airtight container in the fridge for up to 10 days. Can be frozen for up to 2 months.*If you don't want to use pecans, you can use a different type of nut, or marshmallows instead!