place egg whites in a small bowl and let stand at room temperature for 30 minutes. add cream of tartar and beat on medium speed until soft peaks form. gradually beat in sugar, 1 tablespoon at a time, on high until soft glossy peaks form and sugar is dissolved. spread evenly into a well-greased 9-in. pie pan. bake at 275° for 50 minutes. cool on a wire rack.
for filling, melt chocolate in a small heavy saucepan or microwave; sir until smooth. stir in coffee and vanilla. cool to room temperature.
in a chilled small bowl, beat cream until soft peaks form. fold into chocolate mixture. pour into the meringue shell. sprinkle 