Chocolate sin

Jen asked me to post this, so here you go. This cake is scrumptious, but a bit difficult, so if you're a lazy cook, stick with the Duncan Hines cake mix. My pal Estella gave this recipe to me; I'm sure someone somewhere needs to get the credit for it, but I have no idea who, so forgive me.

CHOCOLATE SIN

Butter
Flour
10 oz. semisweet chocolate, broken into small pieces
1/2 cup lightly salted butter, cut into 8 pieces (one stick)
6 large eggs, separated, at room temperature
1 cup granulated sugar
2 teaspoons Kahlua
1/2 teaspoon vanilla
1 1/2 cups whipping cream, well chilled
2 1/2 to 3 tablespoons powdered sugar

Place oven rack in lower one-third of oven; heat oven to 375 degrees. Butter and flour bottom and sides of an 8-inch spring form pan; reserve.

Melt chocolate with 1/2 cup butter. Keep chocolate warm over a pan of warm tap water.

Beat egg yolks in large mixer bowl at high speed, gradually adding 3/4 cup of the granulated sugar. Beat until yolk mixture is pale yellow and thick, 4 to 6 minutes. Add chocolate mixture to the yolk mixture; beat until completely smooth. Add Kahlua and vanilla; beat until blended.

Beat egg whites in medium mixer bowl at high speed until soft peaks form. Gradually beat remaining 1/4 cup granulated sugar into whites; continue beating until stiff but not dry peaks form. Fold whites gently but thoroughly into chocolate mixture. Pour batter evenly into reserved pan; smooth top.

Bake 15 minutes. Reduce oven temperature to 350 degrees; bake another 15 minutes. Reduce oven temperature to 250 degrees; bake 30 minutes longer (total baking time is 1 hour). Turn off oven; prop open oven door and allow cake to remain in oven for 30 minutes. Remove cake from oven and cover top with damp paper towel. Let stand 5 minutes.

Remove toweling and cool cake completely. Dome of cake will crack and collapse; this is normal--press top of cake down lightly to smooth top. Remove springform and transfer cake to serving platter.

Whip cream in chilled mixer bowl on high speed until soft peaks form. Continue beating, gradually adding 1 1/2 tablespoons of the powdered sugar, until stiff peaks form. Dust top of cake with remaining powdered sugar just before serving. Serve cake at room temperature with whipped cream.