In a large mixing bowl, use a fork to combine the crushed graham crackers, sugar, and melted butter. Press mixture into the bottom and up the sides of a 9-inch pie plate. Refrigerate crust while you work on the truffle layer.
In a food processor, pulse 18 of the Key Lime Oreos until broken into fine crumbs. Add the 4 ounces of cream cheese and continue pulsing until well blended. Spread truffle mixture evenly into the crust. Return to the refrigerator.
Melt white chocolate in the microwave until smooth. Allow to cool slightly.
In the well-chilled bowl of a stand mixer fitted with a whisk attachment, beat the heavy cream until soft peaks form. Gradually add powdered sugar and continue whipping until stiff peaks form. Transfer whipped cream to another bowl and place in refrigerator to keep chilled. Return bowl to mixer.
Switch whisk attachment out and replace with paddle attachment. Beat the 8 ounces of cream cheese until smooth. Add melted white chocolate and continue beating. Add lime zest and juice. Beat until light and fluffy.
Remove bowl from the mixer and fold in 1/2-2/3 of the whipped cream. Pour filling over the truffle layer, smoothing out the top.
Transfer the reserved whipped cream to a pastry bag or small ziploc bag with the tip cut off, and decorate the pie as desired. Garnish with the remaining Oreos. Refrigerate for at least 4 hours before serving.
