1. Preheat oven to 350°F.

2. Crush Oreos in a food processor until fine crumbs form. Add 3 tablespoons melted butter and blend until fully incorporated.

3. Press the mixture firmly and evenly into the bottom and up the sides of a 9-inch pie plate.

4. Bake crust for 10–12 minutes until set. Cool completely, then freeze for at least 1 hour.

5. For the ice cream, grind 1 1/4 cups macadamia nuts in a food processor to a coarse paste. Coarsely chop and lightly toast the remaining 1/4 cup nuts for garnish; cool.

6. In a large bowl, whip heavy cream to stiff peaks using a stand or hand mixer.

7. Gently fold in condensed milk until no streaks remain.

8. In a separate bowl, mix macadamia nut paste with vanilla and coconut extract (if using) until blended. Add 1/2 cup whipped cream and mix until lighter and easier to fold.

9. Fold macadamia nut mixture into the whipped cream base just until incorporated. Fold in toasted chopped nuts.

10. Line a medium bowl (one with rim smaller than your crust) with plastic wrap and spray with cooking spray. Transfer ice cream mixture into bowl; cover and freeze 6 hours or overnight.

11. Remove both ice cream and Oreo crust from freezer. Place bowl upside down over crust, then pull gently on plastic wrap to settle ice cream onto the crust. Remove bowl and wrap.

12. Spread fudge topping evenly over ice cream dome. Freeze again until fudge is firm, about 1 hour.

13. Slice and serve each piece topped with whipped cream, extra fudge, and more chopped macadamia nuts.