To prepare the graham cracker crust, toast the graham cracker crumbs with butter, sugar, and a pinch of salt until they become fragrant.
Next, whip the heavy cream until soft peaks form, then set it aside.
For the Key lime filling, beat together the cream cheese, sweetened condensed milk, lime juice, and lime zest until the mixture is smooth and creamy.
Gently fold the whipped cream into the Key lime mixture until everything is well combined.
To assemble, place some of the graham cracker crumbs at the bottom of the jars, then add a layer of the Key lime mousse on top.
Chill the jars until the mousse is set.
When you're ready to serve, top the mousse with tangy whipped cream, additional graham cracker crumbs, and a sprinkle of lime zest.
