Blend gram cracker in a food processor or place crackers in a large reseal able plastic bag, and crush them with a rolling pin until they are finely ground.
Add in a small bowl together with butter vanilla, sugar and nutmeg. Thoroughly mix until fully combine and crumbs slightly comes together.
Press mixture evenly onto bottom of a 9-inch spring form pan. You may use the back of a cup to press it down.
In a large bowl soft cream cheese until fluffy. Gradually beat in sweetened condensed milk until smooth. Stir in key lime juice, vanilla, lime zest , mango and coconut flakes , if using any
Pour the filling into the crust; smooth the top with a rubber spatula. Refrigerate while you make the coconut whipped cream.
Remove canned coconut milk from fridge and carefully scoop out the firm, waxy, thick white layer of coconut cream and add it to your bowl. Throw out the liquid or serve for smoothies or cooking
Whip the coconut cream for 5 minutes or more until it becomes fluffy and light, with soft peaks. Then add the powdered sugar and grated lime zest.
Return whipped cream to fridge for about 5 minutes or until ready to use. Longer periods will make it firmer.
Finally mount the coconut whipped cream on the pie decoratively.
Cover with plastic wrap, and refrigerate until firm, 2 1/2 to 3 hours.
Remove carefully the sides from the spring form pan. You may carefully transfer the pie to a cake stand or serving plate, using the parchment paper. Place on a serving dish and then top with toasted coconut and serve