Butter 10 inch spring form pan. Line with parchment. Butter
and dust parchment with flour. Set aside. Melt chocolate and
butter in top of double boiler. Cool slightly. Set aside 1/4 cups
sugar. In electric mixer beat yolks with remaining sugar for
about 5 minutes, until pale and thick. With mixer on low
speed, add liqueur and juice. Beat just until mixed. Add
and beat until they hold soft peaks. Reduce speed and 1/4
cup sugar. Increase speed until stiff but not dry. Using large
spatula, fold 1 cup of egg white into chocolate mixture. Don't
be too thorough. Fold in 1 more cup. Add remaining whites
and fold carefully only until blended. Turn into prepared pan.
Shake or rotate to level top. Bake in preheated 300º
oven for 1 hour then reduce heat to 250º and bake an
additional 30 minutes. Cake will settle. When finished, turn
oven off. Open door 2 inches and allow cake to cool
completely in oven with heat off. Remove from oven.
Remove sides of pan. Cover cake with rack; invert; remove
pan and parchment lining. Place serving platter on bottom of
cake, invert cake and plate. Serve at room temperature.
Dust with powdered sugar, just before serving.
NOTE: I serve with fresh raspberries and raspberry sauce.
Source: Erna Colum, former owner and pastry chef of
Common House Restaurant (Lois Brann's friend)