1 1/2 cups hazelnuts (6 ounces)
1 1/4 cups granulated sugar
1/4 cup confectioners’ sugar
6 egg whites
Pinch of cream of tartar
Pinch of salt
8 ounces semisweet chocolate
1/2 cup brewed coffee
1 tablespoon Frangelico (hazelnut liqueur), optional
1 teaspoon vanilla extract
2 cups heavy cream
Toasted hazelnuts or shaved chocolate, for garnish
Heat the oven to 250°F. Butter and flour 3 baking sheets. Make sure they can all fit in your oven, even if the edges of 2 overlap slightly. Trace a 10-inch circle onto each sheet.
In two batches in a food processor, grind the hazelnuts with 1/2 cup of the granulated sugar until finely ground. Transfer to a bowl.
Sift the confectioners’ sugar over the ground hazelnuts and toss to mix.
In a large bowl, beat the egg whites until foamy. Add the cream of tartar and salt and beat until the whites begin to peak. Gradually beat in the remaining 3/4 cup sugar, about 1 tablespoon at a time. The meringue will be very stiff.
Fold the ground hazelnuts, one-third at a time, into the meringue. Scoop one-third of the nut meringue onto each circle on the baking sheets and smooth to even 10-inch rounds with a spatula. (Or, if you’re handy with a pastry bag, pipe into rounds.)
Bake for 45 minutes. Turn off the oven but leave the nut meringue layers in the warm oven for 30 additional minutes, until completely dry and crisp. Gently scrape around the edges of the rounds with a spatula to loosen them and transfer to racks to cool.
In a very heavy saucepan or double boiler, melt the chocolate in the coffee over low heat, stirring until smooth. Remove from the heat and let cool, whisking occasionally, until almost room temperature and slightly thickened. Whisk in the Frangelico and vanilla.
In a large bowl, beat the cream until fairly stiff. Fold one-third of the cream into the chocolate to lighten it. Pour the chocolate down the side of the bowl into the remaining cream and fold until no streaks remain.
To assemble the dacquoise, gently place 1 meringue layer on a cake stand or large round serving platter. Scoop a heaping cupful of the chocolate cream on top and spread over the meringue, leaving a 1/2-inch border all around. Put another meringue on top and repeat. Place the last meringue, with the smooth, flat side up, on top and frost the top and sides with the remaining chocolate cream. If the sides look a little messy, refrigerate the dacquoise for about half an hour, or until the cream begins to set up; then smooth out the sides with a long narrow spatula, packing the cream into any gaps that show. Clean off the edge of the cake stand or platter. Garnish the top with the toasted hazelnuts or shaved chocolate and refrigerate until serving time.