How to Make It
Beat heavy cream in bowl of a stand mixer fitted with whisk attachment on medium-high speed for 2 minutes. Add powdered sugar, and beat until stiff peaks form. Reserve 3/4 cup of the whipped cream for topping. Stir chopped cookies into remaining whipped cream.
Line an 8 1/2 x 4 1/2 inch loaf pan with plastic wrap. Pour Oreo cream mixture into prepared pan, and spread in an even layer. Place Oreo Thins in a food processor, and process until finely ground. Add butter and process until combined. Sprinkle crumb mixture evenly over Oreo cream mixture; fold plastic wrap over cake, and freeze at least 8 hours.
Invert cake onto a serving plate; discard plastic wrap. Top with reserved whipped cream, and drizzle with chocolate syrup. Garnish with more cookies if desired.