Angel Pie

Preheat oven to 275°F. Lightly coat a 9-inch pie plate with cooking spray; sprinkle with cornstarch; set aside.

Whisk together 1 tablespoon of the cornstarch and 3/4 cup of the granulated sugar in a small bowl. Beat egg whites and cream of tartar with a stand mixer fitted with a whisk attachment on medium-low speed until frothy, about 1 minute. Increase mixer speed to medium-high; beat until soft peaks begin to form, 1 to 3 minutes. Gradually add sugar mixture to egg white mixture, beating until glossy, stiff peaks form, 3 to 5 minutes. Add 1/2 teaspoon of the vanilla, and beat on low speed until just incorporated, about 5 seconds.

Spread meringue in an even layer on bottom and up sides of prepared pie plate. Bake in preheated oven for 1 hour. Turn off oven without removing meringue; let cool in oven until dried out (some cracks are okay), about 1 hour, 30 minutes. Transfer to a wire rack, and let cool completely, about 30 minutes.

Meanwhile, whisk together egg yolks, lemon zest and juice, and remaining 1/2 cup granulated sugar in a medium saucepan until combined. Add butter; cook over medium-low, stirring constantly, until thickened, 6 to 8 minutes. Transfer lemon curd to a medium bowl; cover surface directly using plastic wrap. Let stand at room temperature until completely cooled, 1 to 2 hours.

Beat cream, powdered sugar, and remaining 1 teaspoon vanilla with a stand mixer fitted with a whisk attachment on medium-high speed until stiff peaks form, 3 to 4 minutes. Reserve 2 cups whipped cream for topping. Whisk 1 cup whipped cream into lemon curd until no lumps remain. Gently fold another 1 cup whipped cream into lemon curd mixture until no streaks remain; gently fold in remaining 1 cup whipped cream. Spread mixture evenly in cooled meringue crust; spread reserved whipped cream evenly over top. Refrigerate, loosely covered, for at least 4 hours or up to 24 hours. Garnish with blackberries, raspberries, and additional lemon zest.