Preheat oven to 350ºF. Combine graham cracker crumbs, sugar, cinnamon, and melted butter in a medium bowl. Press mixture into the bottom of a 9-inch springform pan and bake  for 10 minutes. Remove from oven and allow to cool.

In a stand mixer fitted with the paddle attachment, beat the cream cheese until lightened and creamy. Pour in the sweetened condensed milk and continue beating until smooth. Add the lime juice, lime zest, and salt, and continue mixing until mixture is fully incorporated.

Pour into cooled crust and bake for 15-17 minutes, or until the filling is set. Allow pie to cool for at least 30 minutes before putting it in the refrigerator for at least 3 hours, before serving.

In a medium saucepan, heat the blackberries over medium heat until they soften and their juices start to release, about 3-4 minutes. In a separate bowl, combine the sugar, cornstarch, salt, and cinnamon. Add mixture to the blackberries and continue cooking until it begins to thicken, about 2-3 minutes. Remove from heat and stir in the lemon juice. Pour into a shallow bowl and place in the refrigerator to cool completely.

Just before serving, top pie with blackberry topping. Decorate pie with whipped cream, fresh blackberries and lime slices.