1 (9 inch) pie shell, baked
3/4 cup white sugar
1/4 cup cornstarch
1/3 cup unsweetened cocoa powder
1/4 teaspoon salt
2 cups milk
3 egg yolks, beaten
2 tablespoons butter, softened
1 teaspoon vanilla extract
3 egg whites, beaten
1/4 teaspoon cream of tartar
6 tablespoons white sugar
1/2 teaspoon vanilla extract
Preheat oven to 375 degrees F (190 degrees C).
In 1 1/2 quart casserole dish, mix together sugar, cornstarch, cocoa, salt and 1/2 cup of milk until smooth. Once it is mixed well, stir in remaining milk. Microwave on high for 5 to 8 minutes or until thick; stir halfway through cooking.
In a small bowl, place a small amount of the hot mixture and beat together with egg yolks. Stir back into original mixture in casserole dish. Microwave on high for 1 1/2 to 2 minutes or until thickened; stir frequently. Blend in butter and the 1 teaspoon of vanilla. Pour mixture into pastry shell.
To Make Meringue: In a small bowl, beat egg whites and cream of tartar until foamy. Gradually stir in 2 tablespoons of sugar at a time until stiff peaks form; stir in vanilla. Spread meringue over top of pie filling.
Seal rim of pie with aluminum foil, then bake in preheated oven for about 8 minutes or just until meringue gets browned.