In the work bowl of a food processor, pulse together crackers and sugar until finely ground. Add butter, pulsing to combine. Press cracker mixture into bottom and up sides of a 9-inch pie plate; freeze for 10 minutes.
Bake for 12 minutes. Let cool completely.
In a large bowl, whisk together condensed milk and remaining 4 ingredients until smooth. Pour mixture into prepared crust.
Bake for 15 minutes or until center of pie is set. Let cool completely. Refrigerate for at least 3 hours before serving. Garnish with whipped topping and lime zest and slices, if desired.
Notes
The key to the best Key Lime Pie is using real Key limes. They are less tart than regular limes and are smaller in size. If you can't find real Key limes, using a bottled Key lime juice such as Nellie & Joe's Famous Key West Lime Juice will work just fine.
Recipe by Paula Deen Magazine at https://pauladeenmagazine.com/key-lime-pie-with-saltine-crust-recipe/