For the crust, combine all ingredients in a food processor and blend until crumbs form. Transfer to a round pie dish. Press the crust into the pan firmly.
For the pie filling, blend all ingredients until smooth (no need to clean the food processor after making the crust). Pour the filling over the crust, and refrigerate about 3 hours, or until firm. Or if you can't wait, put in the freezer until firm.
Decorate with crushed nuts, chocolate chips, or chocolate sauce, if desired.
Store left-overs in the freezer and thaw slightly before eating.