1. Preheat oven to 350°. Stir together first 5 ingredients; firmly press mixture on bottom and up sides of a lightly greased 9 1/2-inch deep-dish pie plate. Bake 15 minutes or until lightly browned. Transfer to a wire rack, and cool completely (about 30 minutes).
2. Whisk together egg yolks and next 4 ingredients in a large bowl; pour mixture into cooled crust. Bake at 350° for 25 minutes or until set. Cool completely on a wire rack (about 1 hour).
3. Preheat oven to 375°. Whisk 3 Tbsp. cold water into cornstarch in a 1-qt. saucepan; whisk in 2/3 cup boiling water. Cook over medium heat, whisking constantly, 1 minute or until a thick gel forms. Remove from heat; cool completely (about 30 minutes).
4. Beat 4 egg whites and cream of tartar at medium-high speed with a heavy-duty electric stand mixer, using whisk attachment, until foamy. Gradually add 1 cup sugar; beat until glossy, stiff peaks form. Beat in vanilla and salt. Slowly beat in cornstarch mixture. Beat 3 minutes.
5. Spread meringue over cooled pie, and bake at 375° for 15 minutes or until meringue is golden brown. Transfer to wire rack, and cool completely (about 45 minutes). Serve at room temperature, or cover and chill 8 to 24 hours.