1. Grease an 8 or 9 inch pie pan and preheat oven to 325°F (163°C).
2. Combine graham cracker crumbs, sugar and melted butter in a medium bowl and mix until combined.
3. Press the crumb mixture evenly into the bottom and up the sides of the pie pan, then bake for 8 minutes. Set aside.
4. Add cream cheese, avocado, sugar and key lime juice to a food processor and puree until smooth and well combined. Set aside.
5. Add the heavy whipping cream and powdered sugar to a mixer bowl and whip until stiff peaks form.
6. Gently fold the avocado mixture and the lime zest into the whipped cream.
7. Spread filling evenly into the crust and refrigerate for 4-5 hours, or overnight, until firm.
8. When ready to serve, make the whipped cream. Add the heavy whipping cream. powdered sugar and coconut extract to a mixer bowl and whip until stiff peaks form.
9. Pipe swirls of whipped cream around the edge of the pie. Finish pie off with lime slices and toasted coconut, if desired.