Preheat oven to 350°F (175°C). If making a homemade crust, crush graham crackers and mix with melted butter. Press into a pie dish and bake for 10 minutes until golden.

In a blender, combine avocados, key lime juice, sweetened condensed milk, and a pinch of salt. Blend until smooth and creamy.

Pour the avocado mixture into the cooled crust and chill in the refrigerator for at least 2 hours.

Whip heavy cream in a chilled bowl until soft peaks form. Gradually add powdered sugar until stiff peaks form.

Once chilled, top the pie with whipped cream and garnish with lime slices or zest before serving.