Place 25 Oreo cookies into a food processor and pulse into fine crumbs. Melt 4 tablespoons of unsalted butter in a separate bowl and mix with the crumbs. Press into a 9-inch deep dish pie pan.

In a stand mixer, combine 3 cups of heavy cream, ½ cup powdered sugar, and 2 tablespoons of instant espresso powder. Whip on high speed for 6-7 minutes until stiff peaks form.

Gently fold in 14 ounces of sweetened condensed milk with a spatula, mixing for about 1 minute on low speed.

Pour the filling over the prepared crust, smoothing the top. Freeze uncovered for at least 6 hours until firm.

Let the pie thaw for about 10 minutes before slicing. Use a sharp knife dipped in hot water for clean cuts.