Melt chocolates over a bain-marie; stirring up every so often (Do not go over 122/50ºC). As soon as it is melted, remove from heat; set aside. Melt butter without boiling it. Mix chocolates with hazelnut spread first. Add butter and the dried crushed crepes. Spread mixture onto a silicone baking mat, or parchment. Top with another silicone mat, and roll out into an 0.3-inch/0.75cm thick sheet. Do not roll out too thin. Each cookie should weight ≈ 0.9 ounces/25grams. Freeze cookie sheet for about 20 min, or until firm to the touch.

Cut cookie out into desired shapes. Freeze again and transfer hardened cookies onto another tray. Leave scraps at room temperature to soften – and make another sheet. Repeat steps until done. Keep cookies in the freezer until ready to coat.