Preheat oven to 350 degrees F (175 degrees C).

In a food processor, combine crushed Oreo cookies, melted butter, and crushed nuts.

Pulse until the mixture forms a crumbly texture.

Press the mixture into a greased pie pan, forming an even crust.

Bake for 10 minutes.

Remove from oven and let cool completely.

In a large bowl, whip the whipping cream until stiff peaks form.

Add vanilla extract and Kahlua liqueur to the whipped cream and gently fold together.

Gently fold in the softened coffee ice cream and crushed Heath candy bars.

Pour the ice cream mixture into the cooled Oreo cookie crust.

Freeze for at least 3 hours, or until firm.

Remove from freezer 15 minutes before serving to soften slightly.

Garnish with remaining crushed cookies, whipped cream, and chocolate shavings.