Foolproof Key Lime Pie

Lime pie is considered a classic for a reason - it has an unsurpassed taste that no one can resist. Whip up this reliable lime pie that your guests are sure to enjoy. As a last resort, you can use regular limes, but when it comes to fresh juice rather than bottled, the real one always wins.
Preheat the oven to 350 degrees. Combine the cracker crumbs, sugar, and 1/8 teaspoon salt in a bowl, mixing well. Drizzle the crumb mixture with the butter; stir with a fork until the crumbs are moist. Squeeze the crumble mixture into the bottom and top sides of a 9-inch glass or ceramic pie dish. Bake for 8 minutes; let cool on a wire rack.Whisk together 1/3 cup cream, 2 teaspoons lime zest, lime juice, milk, eggs, and the remaining 1/8 teaspoon salt in a bowl until smooth. Pour the mixture over the cooled cake pan. Bake for 15 minutes. Remove from the oven; let cool for 15 minutes. Refrigerate for 2 hours or until set.Combine the powdered sugar, vanilla, and remaining 2/3 cup cream in a bowl. Beat with an electric mixer on high speed until soft peaks form. Sprinkle the pie with whipped cream; garnish if desired.