Preheat oven to 325°F. Combine crushed cookies (see Tip#1 below), melted butter and brown sugar; transfer to 9” pie plate. Using your fingers, press crumbs evenly onto bottom and up side of pie plate. Bake for about 10 minutes or until firm; let cool on rack.
Meanwhile, in saucepan, whisk together coconut milk, sugar, cornstarch and salt; stir in cream of coconut. Bring to boil over medium heat, stirring constantly; cook, stirring, for about 6 minutes or until thickened.
Add egg yolks to a large bowl and stir in half the coconut mixture; pour mixture back into saucepan. Cook, stirring, for about 3 minutes or until thickened. Remove from heat. Stir in rum (if desired), vanilla and ½ teaspoon cinnamon; pour into pie shell. Press plastic wrap onto filling; refrigerate for at least 2 hours.
Before serving, whip cream until stiff peaks form; spread over pie. Sprinkle with toasted shredded coconut (see Tip #2 below) and remaining cinnamon.
To crush cookies, place cookies in resealable plastic bag; pound with a rolling pin, or the bottom of a saucepan, until finely crushed. To toast coconut, preheat oven to 350°F. Spread coconut on baking sheet; bake, stirring occasionally, for about 10 minutes or just until golden brown. Let cool before using.