Preheat oven to 350 degrees F and line 2 baking sheets with parchment or silpat liners.
Place Thin Mints in food processor and pulse until finely ground.
Transfer ground cookies to a medium bowl and add softened cream cheese. Mix until well combined, I use my hands, it’s much easier!
Cut each sheet of puff pastry into 9 rectangles totaling 18.
Spead cookie/cream cheese mixture over 9 rectangles then top with remaining 9, crimp edges with fork and poke a few holes on top to allow for steam to escape.
Whisk egg white and water and brush lightly over each streudel.
Sprinkle tops with granulated sugar and bake for 25-30 minutes or until puffed and golden brown.
Remove and let cool for 5 minutes.
Place powdered sugar and heavy cream into a bowl, mix until smooth. Drizzle over warm streudels and serve. Can be enjoyed chilled as well.