Whisk yolks and eggs in a medium bowl to blend. Combine lemon juice, butter, and sugar in large metal bowl. Set bowl over saucepan of simmering water; whisk until butter melts and sugar dissolves. Gradually whisk 1/3 of hot butter mixture into eggs, whisk mixture back into bowl with remaining butter mixture set over simmering water. Whisk constantly until custard thickens and thermometer inserted into mixture registers 180°F, about 5 minutes (do not boil). (If you don’t have a candy thermometer, wait until the mixture thickens and coats the back of a wooden spoon.) Pour lemon curd through strainer set over medium bowl. Place plastic wrap directly on surface of lemon curd; chill overnight. (Can be made up to 2 days ahead. Keep refrigerated.)
4 large egg yolks, 3 large eggs, 1/2 cup fresh lemon juice, 1/2 cup unsalted butter, 1/2 cup granulated sugar
Finely grind almonds in processor. Using hand mixer or stand mixer, beat butter, powdered sugar, and lemon peel in a medium bowl until well blended. Add yolk and beat until smooth. Beat in ground almonds, then flour, and salt. Gather dough into ball; flatten into disk.
1/2 cup almonds, 1/2 cup unsalted butter, 1/3 cup powdered sugar, 1 tablespoon packed finely grated lemon peel, 1 1/4 cups all-purpose flour, 1/4 teaspoon fine sea salt, 1 large egg yolk
Preheat oven to 350°F. Press crust onto bottom and up sides, about 1-inch, of a 9-inch-diameter tart pan or spring-form pan with removable bottom. Chill 20 minutes. Bake crust until golden brown and cooked through, pressing with fork if crust bubbles, about 25 minutes. Cool crust in pan on rack. (Can be prepared 1 day ahead. Cover and store at room temperature.)
Make lemon cream filling
Using electric mixer, beat whipping cream, sugar, lemon peel, and lemon extract in large bowl until stiff peaks form.
1 ½ cups chilled heavy whipping cream, 3 tablespoons sugar, 1 tablespoon finely grated lemon peel, ¼ teaspoon lemon extract
Spoon half of lemon curd and half of lemon cream into another large bowl. Using a small silicone spatula, gently fold curd and lemon cream together, creating a marble effect and being careful not to over mix to retain marbling. Spoon marbled mixture in dollops into cooled crust. Using tip of knife or small spatula, swirl and pull mixture upwards in peaks. Repeat with remaining curd and lemon cream mixture. Refrigerate pie at least 1 hour, or until set. Remove pan sides. Place pie on platter. Serve with salted caramel sauce.
Make caramel sauce
In a medium saucepan, combine the sugar, water and corn syrup and bring to a boil. Using a wet pastry brush, wash down any crystals on the side of the pan. Boil over high heat until a deep amber caramel forms, swirling often, about 6-12 minutes (be careful, as it will darken rapidly once it reaches that stage). Remove the saucepan from the heat and carefully whisk in the cream. Whisk in the butter, and whisk in the salt. Let the caramel cool to room temperature. The salted caramel sauce can be refrigerated for up to 2 weeks. Rewarm before serving. Recipe for caramel makes more than you will need for the pie.
1/4 cup water, 2 tablespoons light corn syrup, 3/4 cup heavy cream, 4 tablespoons unsalted butter, 1 & 1/2 teaspoons Fleur de Sel, 1 cup sugar
Keep pie covered and refrigerated for up to 5 days.Nutrition analysis is without the caramel sauce.