Chocolate Chestnut Torte

15 ounces chestnut puree or chestnut cream
4 ounces unsalted butter
1 teaspoon vanilla
6 eggs, separated
10 ounces semisweet chocolate, melt and cool
1 pinch salt
1/4 cup sugar
6 ounces semisweet chocolate, coarse chopped
1/2 cup whipping cream or brewed coffee
10 ounces frozen raspberries, pureed + 2 tbl. sugar

Preheat the oven to 350ºF. Line a 9- or 10-inch springform pan with a circle of baking parchment. In a large bowl, using a whisk, or an electric mixer, combine the chestnut puree or cream with the butter or margarine until well blended. Mix in the vanilla, the egg yolks, and the melted chocolate and blend well.

In another clean bowl, with clean, dry beaters, gently whip the egg whites with the salt, just to break up and foam the whites slightly. Then gradually increasing the mixer speed, dust in the sugar to form stiff, glossy (but not dry) peaks. Fold one third of the egg whites into the chestnut mixture and work it in well to lighten. Then, gently fold in the remaining egg whites in two installments, blending well but taking care not to deflate the mixture.

Spoon the batter into the prepared pan and bake for 35 to 45 minutes. The cake will rise somewhat and look dry and slightly cracked on top when done. The middle should be soft but firm. Cool in the pan for 20 minutes, then remove to a wire rack. Freezes well.

Ganache Glaze: Bring the whipping cream (or coffee) to a boil and add the chopped chocolate all at once. Remove from the heat and stir briskly, using a wire whisk, until all the chocolate melts and you have a thick glaze or sauce-like topping. Invert the cake (so that the smooth, flat bottom faces up) and put it on a wire cake rack set over a cookie sheet. Pour the glaze over the cake, using a metal spatula to even the glaze out and spread it along the sides. Serve with a dollop of whipped cream on the side or a pureed raspberry sauce. Or, garnish with chocolate shavings dusted with sifted powdered sugar.