1. Preheat oven to 300 degrees. Line 2 large cookie sheets with foil. Using 8 inch round cake pan as a guide, with toothpick, outline 2 circles on foil on each sheet. In food processor with knife blade attached or in blender, blend hazelnuts, cornstarch, and 3/4 cup confectioners sugar until nuts are ground.
2. Use a large bowl and beat egg whites and cream of tartar at high speed until they form soft peaks. Sprinkle 3/4 cup confectioners sugar, 2 tablespoons at a time, into egg whites, beating well after each addition. Beat until sugar dissolves and whites stands in stiff, glossy peaks.
3. With rubber spatula, fold hazelnut mixture into egg whites. With metal spatula, spread one fourth of meringue mixture inside each circle on cookie sheets. Bake meringues 45 minutes. Turn oven off and leave in oven 1 hour to dry.
4. Transfer meringues with foil to wire racks and cool completely. With metal spatula, carefully loosen and remove meringues from foil.
5. Prepare chocolate cream: In small bowl, with mixer at medium speed, beat 1 1/2 cups heavy cream, 1 tablespoon confectioners sugar and 1/2 teaspoon vanilla just to soft peaks. With rubber spatula, fold half of whipped cream into slightly warm melted chocolate just until combined. Fold in remaining whipped cream. Reserve 1/4 cup chocolate cream.
6. Prepare coffee cream: In cup, dissolve espresso in 2 tablespoons heavy cream. In small bowl, beat remaining heavy cream and 3 tablespoons confectioners sugar until soft peaks form. Add espresso mixture; beat until stiff peaks form.
7. On cake stand or plate, place 1 meringue layer; spread with half of the chocolate cream. Top with another meringue layer and half of the coffee cream. Repeat layering, ending with coffee cream. Spoon reserved 1/4 cup chocolate cream on top. Refrigerate dacquoise at least 5 hours, or overnight, for easier cutting. Prepare chocolate curls or strawberry slices just before serving!