Step 1Heat the oven to 350 degrees. Line 3 baking sheets with wax paper or baking parchment. Trace 2 circles on each of two baking sheets, 8 inches in diameter, with 1 inch between them. On the third sheet, trace one circle. Brush the paper with melted butter and flour generously, shaking off the excess.
Step 2Beat the egg whites to soft peaks. Gradually beat in the sugar and continue beating until stiff and glossy. Fold in the flour and the ground almonds.
Step 3Divide the egg white mixture among the circles on the baking sheets, taking care to spread it evenly to the edges of the circles as thin spots will be fragile.
Step 4Place the sheets in the oven, reduce the heat to 250 degrees and bake for about 25 to 35 minutes, or until the layers are just beginning to color. Reduce the heat to 200 and bake for two more hours.
Step 5Remove the meringues and cool briefly so they can be handled. Peel the parchment paper from the bottom of the disks, trying not to break them but not minding if you do -- icing will conceal it.
Step 1As the meringues cool, make the filling. In a double boiler, melt the chocolate and butter together; remove from heat.
Step 2Beat the egg whites until foamy and soft but not until stiff peaks form. Gradually beat in the sugar and cocoa and then the melted chocolate and butter.
Step 3Put a meringue disk on a good pastry dish. Coat it with icing. Place a disk on top of the icing. Ice. Repeat with the remaining disks, finishing with a layer of icing. Serve immediately. The Italian walnut liqueur Nocino would be the ideal accompaniment.