Position a rack in the lower third of the over and preheat to 375 degrees.
In a small bowl, combine the grappa and currants. Set Aside.
In a food processor, pulse the almonds and semolina flour until the almonds are very finely ground. Set aside.
Melt the chocolate and butter in a heatproof bowl placed in a skillet of barely simmering water, or in the top of a double boiler, stirring occasionally until melted and smooth. Remove from heat. Or microwave on MEDIUM (50%) power for about 2 1/2 to 3 minutes. Stir until smooth and completely melted.
In a large bowl, whisk egg yolks with 2/3 cup of the sugar and the salt until pale and thick. Stir in the warm chocolate mixture and the grappa and currants. Set aside.
In a clean, dry mixer bowl, beat the egg whites and cream of tartar at medium speed until they are white and foamy. Gradually sprinkle in the remaining 1/3 cup granulated sugar, beating at high speed until almost stiff. Scrape about one-fourth of the egg whites on top of the chocolate mixture and sprinkle all of the almond mixture over the top. Fold together. Fold in the remaining whites. Scrape the batter into the pan. Sprinkle the top with pine nuts. For the 9-inch pan, bake 20-25 or until a toothpick or wooden skewer plunged into the cake about 1 1/2 inches from the edge of the cake comes out clean. The center of the cake will jiggle slightly when the pan is jostled and will still be gooey if tested. Set the cake on a rack to cool completely. The surface of will crack and fall as it cools. Cake may be prepared to this point and keep, covered, at room temperature for 2 to 3 days or frozen for up to three months. Bring to room temperature before serving.
Slide a slim knife around the sides of the cake to release it. Remove the pan sides and transfer the cake, right side up, to a serving platter. Sprinkle a little powdered sugar over the top before serving.