Preheat the oven to 350℉ (177℃).
Finely crush the saltine crackers in a food processor or with a heavy duty ziploc bag and a rolling pin. Add the melted butter and sugar, mixing until evenly moistened.
1 1/2 sleeves saltine crackers, 1/2 cup salted butter, 1/4 cup granulated sugar
Firmly press the crust mixture into the bottom and sides of a 9-inch pie plate. It makes a thick crust and may be crumbly, but should hold. Freeze the crust for 10 minutes.
Bake for 16-20 minutes until lightly golden brown. This will help set the crust and give it a nice toasty flavor and crunch. Set aside.
In a large mixing bowl, whisk together the sweetened condensed milk and egg yolks until smooth. Add the lime juice and lemon juice, whisking again until combined. Pour the mixture into the prepared crust.
1 (14-ounce) can sweetened condensed milk, 4 large egg yolks, 1/4 cup fresh lime juice, 1/4 cup fresh lemon juice
Bake for 15 minutes until just set. Transfer the pie to a cooling rack and cool at room temperature for 1 hour, then transfer to the fridge to chill for 2 hours.
Just before serving, beat the cream, powdered sugar, and vanilla in a large bowl with an electric mixer on high speed until medium-stiff peaks form.
1 1/2 cups heavy whipping cream, 1/4 cup powdered sugar, 1 teaspoon pure vanilla extract
Pile the whipped cream on top of the chilled pie leaving a small border visible underneath to show the filling and sprinkle with lime zest, lemon zest, or both. Slice and serve cold.
Lime or lemon zest,