Instead of flour, this moist dense cake is made with ground almonds that are first toasted for extra flavor.
Preheat oven to 375 degrees F. Lightly grease and flour the pan and line the bottom with parchment paper.
In the top of a double boiler or in a bowl placed over a pan of simmering water, melt the chocolate and coffee, stirring frequently. Set aside to cool slightly.
With a hand held mixer, or heavy-duty mixer with the paddle attachment, beat the butter and 3/4 cup of the sugar until ivory colored. Add the egg yolks, two at a time. Continue to beat until the mixture is light and airy. Fold in the chocolate.
In a clean dry bowl using clean dry beaters, whip the egg whites with the salt until soft peaks form when the beaters are lifted. Gradually beat in the remaining two tablespoons sugar until the egg whites are stiff but not dry. Fold the ground almonds into the whites. Fold the chocolate mixture into the egg white mixture.
Scrape the batter into the prepared pan and spread it evenly. Place the pan in the oven and immediately turn the heat down to 350 degrees F. Bake 15 minutes. Turn the oven down to 325 degrees F. Bake an additional 45 minutes. Turn the oven down to 300 degrees and bake 15 to 20 minutes. Turn the oven off and leave in the oven, with the door ajar, for another 30 minutes.
Cool on a rack. Remove the sides of the pan and transfer to a serving platter. Sprinkle with confectioners’ sugar. Serve slices with whipped cream, if desired.