In a food processor or with a zipper bag and rolling pin, grind up the gingersnap cookies into very fine crumbs.

Pour the melted butter evenly over the crumbs. Add the salt and mix until the crumbs look like wet sand.

Press the crumbs into a 9-inch pie plate in an even layer on the bottom and sides of the plate. Transfer to the freezer.

In a medium mixing bowl, beat the cream cheese until smooth, then mix in the sweetened condensed milk. Beat in the lime juice in two additions.

In a medium mixing bowl, whip the heavy cream and powdered sugar until thickened and holding its shape. Using a rubber spatula, gently fold the whipped cream into the cream cheese mixture in three additions.

Evenly spread the filling into the crust. Chill, covered, for at least 6 hours but overnight is best.

Top with whipped cream, cranberries (or sugared cranberries) and lime slices, if desired.