Preheat the oven to 350˚. Coat the bottom and sides of a 9-inch pie plate with vegetable oil. Pulse the graham crackers and sugar in a food processor until finely ground. Add the vegetable oil and coconut oil and pulse until the mixture looks like wet sand. Press the mixture into the bottom and up the sides of the prepared pie plate. Bake until set, 12 to 15 minutes. Transfer to a rack; let cool completely.
Clean out the food processor. Add the avocados, cream of coconut, lime zest and juice and salt and puree until smooth. Pour the mixture into a large bowl and fold in the whipped topping until combined. Spoon the filling into the crust and smooth the top. Freeze until firm, about 6 hours. Serve with more whipped topping.
We used coconut whipped topping for this recipe: It adds extra coconut flavor and makes the pie dairy-free.