Preheat oven to 300°F.
Grease and flour 9 inch metal pie pan.
In small bowl, with mixer at high speed, beat egg whites, salt, and cream of tartar until soft peaks form.
Beating at high speed, add 1 teaspoon vanilla and sprinkle in 1 cup confectioners' sugar, 2 tablespoons at a time, beating well after each addition until sugar dissolves and whites stand in stiff, glossy peaks.
With metal spatula, evenly spread meringue over bottom and up side of pie pan, making an edge above pie pan rim.
Bake meringue 1 hour.
Turn off oven and let meringue remain in oven 1 hour to dry out.
Cool meringue shell in pie pan on wire rack.
Meanwhile, prepare filling: Sift cocoa with remaining 1 1/4 cups confectioners' sugar.
In cup, dissolve espresso powder in 1 teaspoon hot tap water.
In large bowl, with mixer at medium speed, beat heavy or whipping cream, dissolved espresso, and remaining 1 1/2 teaspoons vanilla just until soft peaks form.
Reduce speed to low; gradually beat in cocoa mixture until thoroughly blended and stiff peaks form (do not overheat).
Beat in milk.
With rubber spatula, spread chocolate cream into cooled meringue shell.
If not serving pie right away, cover and refrigerate until ready to serve.
Garnish with chocolate curls.