Adapted from Cook's Country, Alton Brown, and me
1 cup plus 2 tablespoons cake flour
I/4 teaspoon salt
1 3/4 cup granulated sugar, whizzed in food processor about a minute to make extra fine
12 egg whites, at room temperature
1 1/2 teaspoons cream of tartar
1 teaspoon vanilla
Preheat oven to 325º. Adjust oven rack to lower middle postition.
Remove half of sugar from food processor. Add flour to sugar in the processor and process about a minute.
Beat egg whites and cream of tartar with mixer on medium low till frothy. Increase speed to medium high and slowly add in reserved sugar. Beat till soft peaks form, about 6 minutes. Add vanilla and mix to combine.
Sift the flour and sugar mixture, and gently fold into egg white mixture in 3 additions. Put batter into ungreased angel food cake pan with removable bottom, then smoothing top.
Bake 40-45 minutes, till toothpick inserted into a crack comes out clean. Invert cake and cool for about 3 hours. To remove, use knife to cut between pan and cake.
1 3/4 cups whipping cream
12 ounces semi-sweet chocolate chips
3 ounces strong coffee
1 tablespoon Kahlua
4 tablespoons butter
1 teaspoon plain gelatin (I use Knox brand)
Whipped Cream Icing:
I cup whipping cream
1/2 cup powdered sugar, sifted
1 envelope Whip It, whipped cream stabilizer, optional
1 teaspoon vanilla
Melt, chips, coffee, Kahlua and butter together in the microwave, stirring and stopping every 30 seconds till smooth. Cool till just slightly warm. Sprinkle gelatin over 1/4 cup of the cream in small bowl and let sit for 5 minutes. Add gelatin to chocolate when chocolate has cooled.
Whip the remaining 1 1/2 cups cream till soft peaks form. Fold 1/4 cup into chocolate, then fold half the remaining cream, followed by the last half of the whipped cream. Refrigerate about an hour.
To assemble cake, slice off about an inch down. Set aside top. Cut out a trench in bottom of cake, making sure not to get too close to bottom or edges. Save removed cake pieces for snacking. Fill trench with mousse and top with reserved round of cake.
To make icing, whip cream with sugar, Whip It and vanilla. Frost cake. Chill before serving.