Place 25 cookies in the bowl of a large food processor. Process until finely crushed, about 1 minute. Add the melted butter and pulse to combine. Press the Oreo mixture firmly into the bottom and up the sides of a buttered deep-dish, 9-inch pie plate. Place in the freezer while you make the filling (at least 15 minutes).

In the bowl of an electric mixer fitted with the whisk attachment, beat the heavy cream on medium-high speed until stiff peaks form, 1 to 2 minutes. Transfer the mixture to a large bowl and set aside.

In the same bowl used to beat the cream (no need to wipe it clean), combine the cream cheese, sour cream, powdered sugar, and vanilla. Using the paddle attachment, beat on medium-high speed until light, fluffy, and smooth, about 1 minute, scraping the sides and bottom of the bowl as needed. Transfer the mixture to the bowl with the whipped cream and fold to combine.

Reserve 8 of the remaining cookies and place the remaining 9 cookies in a zip-top plastic bag. Tap the bag with a rolling pin to lightly crush the cookies. Add to the cream cheese mixture and fold to combine.

Transfer the mixture to the chilled pie crust and smooth the top. Cover and refrigerate for at least 4 hours or overnight.

Just before serving, press 8 cookies flat into the top of the pie. Slice and serve with dollops of whipped cream and a sprinkle of any extra cookie crumbs.