Start by crushing the chocolate sandwich cookies into fine crumbs. You can do this by placing them in a ziplock bag and using a rolling pin or by pulsing them in a food processor.
In a mixing bowl, combine the crushed cookies with 1 cup of whipped cream and the vanilla extract. Mix until well combined, forming a thick and cohesive mixture.
Line a 9×13-inch baking dish with parchment paper for easy removal later. Spread half of the cookie mixture evenly across the bottom of the dish, pressing down firmly.
Next, take your favorite ice cream, softened slightly for easier spreading, and layer it over the cookie crust. Use a spatula to smooth it out evenly.
Drizzle chocolate syrup over the ice cream layer. If you want to add a bit more texture, you can sprinkle some chopped nuts or additional crushed cookies on top.
Spread the remaining cookie mixture over the ice cream layer, pressing it down gently to create a second layer.
Cover the dish with plastic wrap and place it in the freezer for at least 4 hours, or overnight for best results.
Once frozen, remove the cake from the dish using the parchment paper. Cut into squares and serve immediately, topping with extra whipped cream, sprinkles, or chocolate syrup if desired.