1½ cups margarine
12 ounces semisweet chocolate, cut in small pieces
12 extra-large eggs
1-¾ cup sugar
Unsweetened cocoa powder
Preheat oven to 325 degrees. Cut a circle of waxed paper to fit a 10-inch spring form pan and place paper in bottom of pan.
In a saucepan, melt margarine and remove from heat. Add chocolate and stir until melted, about 3 minutes. Let mixture cool slightly (2-3minutes). Separate the eggs, keeping all the yolks and 7 of the whites. Place the yolks in a large bowl, add the sugar, and beat until the mixture forms pale yellow ribbons. Add the chocolate mixture, mix well and set aside.
Beat whites in another large bowl just beyond point where soft peaks form (do not beat until stiff). Fold whites into chocolate mixture gently but thoroughly. Reserving one cup at room temperature pour batter into prepared pan.
Bake until tester inserted in center comes out clean, about 1½ hours. Let cake cool 10 minutes in the pan, then unlatch the tin and take off the ring.
Remove the top crust of the cake with a sharp serrated knife and reserve. Using a spatula (and your hands) press down around the sides of the cake to level the top. Let cool 10 minutes more. Invert cake onto platter. Let cool completely.
Frost top and sides of cake with reserved mixture. Crush reserved crust between two sheets of waxed paper using a rolling pin. Pat onto sides of cake. Dust the top with cocoa powder.