6 oz Bittersweet chocolate
-(OR Semisweet chocolate),
- chopped
2 oz Unsweetened chocolate
- chopped
1/3 c  Freshly brewed espresso
1 c  Unsalted butter
1 tb Vanilla extract
6 lg Eggs; separated, room temp.
1 c  Dark brown sugar; packed
1/2 c  Sugar
1/3 c  All-purpose flour, sifted
Powdered sugar

Position rack in center of oven and preheat to 350 F. Butter
10-inch-diameter springform pan with 2-inch-high sides. Melt both
chocolates with coffee and butter in heavy medium saucepan over medium-low
heat, stirring until smooth. Pour into large bowl. Cool. Mix in vanilla
extract. Using electric mixer, beat yolks with both sugars in medium bowl
until slowly dissolving ribbon forms when beaters are lifted. Fold yolk
mixture into chocolate mixture. Fold in flour. Using electric mixer fitted
with clean, dry beaters, beat whites in another large bowl until almost
stiff. Fold 1/4 of whites into chocolate mixture to lighten. Gently fold
in remaining whites. Gently pour batter into prepared pan. Bake until
toothpick inserted in center comes out with moist crumbs still attached,
about 45 minutes. Transfer to rack and cool (cake will fall). (Can be
prepared 1 day ahead. Cover cake in pan with plastic wrap and let stand at
room temperature.) Run small knife around cake pan sides to loosen if
necessary. Release pan sides of cake. Invert cake onto plate. Place
stencil or doily atop cake. Sift powdered sugar over. Remove stencil from
cake and serve.