1-1/4 cups all-purpose flour
1/4 teaspoon salt
1/2 cup cold butter
3 to 5 Tablespoons ice cold water
3/4 cup sugar
5 Tablespoons baking cocoa
3 Tablespoons cornstarch
1/4 teaspoon salt
2 cups whole milk
3 large egg yolks, room temperature, beaten
1 teaspoon vanilla extract
3 large egg whites, room temperature
1/4 teaspoon cream of tartar
6 Tablespoons of sugar
Cut cold butter into flour until crumbly.
Gradually add ice cold water, tossing with fork until dough holds together when pressed. Shape into disk; wrap and refrigerate.
On lightly floured surface, roll dough in 1/8-inch thick circle; transfer to 9 inch pie plate.
Trim to 1/2-inch beyond rim of the plate; flute edge.
Refrigerate 30 minutes. Preheat oven to 425ºF.
Line un-pricked crust with a double thickness of foil.
Fill with pie weights, dried beans, or uncooked rice.
Bake on a lower oven rack until edges are light golden brown, 15 to 20 minutes. Remove foil and weights; bake until bottom is golden brown, 3-6 minutes longer. Cool on a wire rack. Reduce oven setting to 350ºF.
In saucepan, mix sugar, cocoa, cornstarch and salt; gradually add milk.
Cook and stir over medium heat until thickened and bubbly.
Reduce heat; cook and stir 2 minutes more and then remove from heat.
Stir 1 cup of hot filling into egg yolks. Return to saucepan, bring to gentle boil.
Cook and stir 2 minutes. Remove from heat and stir in vanilla.
Pour hot filling into pie crust.
Immediately beat egg whites with cream of tartar until soft peaks form.
Gradually add sugar and continue to beat until stiff and glossy.
Spread evenly over hot filling sealing meringue to pie crust.
Bake until meringue is golden brown, 12 to 15 minutes.
Cool 1 hour on a wire rack. Refrigerate at least 4 hours before serving.