Crumbs: In a food processor or blender, pulse the Oreos until they are fine crumbs. You should get about 2 cups.
Make crust: Stir in the 5 Tablespoons melted butter, 1 Tablespoon sugar, and a pinch of salt until combined. Press up the sides and into the bottom of a 9-inch pie plate. You can use a measuring cup to press the mixture firmly into the pan.
Cheesecake
Beat: In a large mixing bowl, use a hand mixer to beat 12 ounces cream cheese, 1/4 cup sugar and 1 teaspoon vanilla extract. Beat until creamy and smooth, and set aside.
Whip cream: In a different large mixing bowl, use the hand mixer to whip 2/3 cup whipping cream, 6 Tablespoons powdered sugar. Whip at a high speed, until the cream has stiff peaks.
Make Oreo crumbs: Place 8 Oreos into the previously used blender or food processor and make crumbs.
Combine: Gently fold the whipping cream into the cheesecake mixture until combined. Add Oreo crumbs and pieces and stir gently. You can save a Tablespoon of the Oreo crumbs to sprinkle on top later, if desired.
Chill: Spread the cheesecake filling into the prepared crust and chill for at least 5 hours, or overnight.
Topping
Make whipped topping: In a large mixing bowl, whip 3/4 cup whipping cream, 6 Tablespoons powdered sugar and 1/2 teaspoon vanilla until stiff peaks form.
Top cheesecake: Spread or pipe topping over the cheesecake. Add reserved oreo crumbs and halved oreos for garnish. Keep in refrigerator until ready to serve.
Notes
Store leftovers in the refrigerator. Best if eaten in 3-4 days.