Preparation / Directions:
Preheat the oven to 325 degrees. Line a 9-inch springform pan with baking parchment paper and butter the paper lightly. Melt the chocolate in the top of a double boiler over low heat. When the chocolate is completely melted (it should be barely warm), add the softened butter and stir.
Since the butter is at room temperature it should melt into the chocolate without additional heat; if necessary, return the pan to low heat and stir until the butter melts. Transfer the chocolate mixture to a large bowl and set aside.
Whisk the 7 egg whites with 3/4 cup of the sugar until the meringue is shiny and can hold a stiff peak; set aside.
Whisk 6 of the egg yolks with the remaining 1/2 cup sugar until the mixture is creamy and the sugar is almost dissolved. Add the vanilla and 1 teaspoon of the rose water and mix well.
Add 1/4 of the chocolate mixture to the egg yolk mixture and combine well; then add all of the egg yolk-chocolate mixture to the remaining chocolate-butter mixture and combine well. Add 1/3 of the meringue to the egg yolk-chocolate mixture and stir in well. Using a rubber spatula, fold in the remaining 2/3 of the meringue until the mixture has a mousse-like texture.
Pour the batter into the prepared pan. Spread the batter, slightly mounding it in the center of the pan. Bake for 60 to 70 minutes, until set. The cake will remain soft inside so there is no need to "test" it; however, the cake should not appear runny. The cake will rise wonderfully and then collapse. Cool completely.
Press gently on the top of the cake to create an even surface. Sprinkle with 1 teaspoon of the rose water (or liqueur). Turn over onto an 8-inch cardboard cake base (available at bakery cookware supply stores or use a large plate).
Sprinkle with the remaining 1 teaspoon rose water.
If using sweetened whipped cream, whip the cream with the confectioners' sugar and vanilla and then spread over the top of the cake. Take the blade of a spatula, place it on the surface of the cake and gently lift up, creating peaks to give it a "truffle" effect. To complete the effect, sift unsweetened cocoa over the whipped cream to cover.
Wrap well and chill for a few hours or overnight. Serve at room temperature. Sprinkle with confectioners' sugar before serving, if desi