Peanut Butter Meringue Pie

Step 1
Preheat oven to 350 degrees F (175 degrees C).

Step 2
Beat confectioners' sugar and peanut butter together in a bowl with an electric mixer until smooth. Spread peanut butter mixture into prepared pie crust as evenly as possible.

Step 3
Whisk water, cornstarch, and 1 tablespoon white sugar together in a saucepan; bring to a boil for 15 seconds, stirring constantly. Remove saucepan from heat and cover with a lid.

Step 4
Beat egg whites in a glass or metal bowl until soft peaks form. Lift the beater or whisk straight up: the egg whites will form soft mounds rather than a sharp peak.

Step 5
Beat cream of tartar and vanilla into egg whites. Gradually add 1/2 cup white sugar, continuing to beat until stiff peaks form. Lift the beater or whisk straight up: the egg whites will form sharp peaks.

Step 6
Beat cornstarch mixture into egg white mixture on lowest speed, 1 tablespoon at a time. Increase speed to medium and beat egg whites for 10 seconds to form meringue. Spread meringue over peanut butter mixture to the edges of the pie crust.

Step 7
Bake in the preheated oven until meringue peaks are golden, 10 to 15 minutes.