Chocolate Crater Cake

8 squares (8 oz.) bittersweet chocolate

1/3 C. salted butter

4 egg whites, at room temperature

3/4 C. granulated sugar

4 egg yolks

finely grated peel of 1/2 orange or 1 lemon, about 1 t. (optional)

1 1/2 t. vanilla

1/4 t. salt

Topping:

1 1/2 cups whipping cream

1 T. Grand Marnier or other orange liqueur (optional)

1 t. vanilla

Shaved chocolate or cocoa powder (optional)

Preheat oven to 325°F. Line bottom of an 8-1/2-inch springform pan with waxed paper. Butter pan and paper. Then, sprinkle lightly with flour. Shake until evenly coated with flour, then shake out excess.

To make cake, cut chocolate into coarse pieces. Place chocolate and butter in a small heavy-bottomed saucepan set over very low heat. Melt, stirring frequently, then remove from heat when small pieces of chocolate are still visible, about 5 minutes. Stir until smooth. Or, place chocolate and butter in a microwave-safe bowl. Microwave, without stirring, on medium until chocolate is almost but not completely melted, about 3 minutes. Stir until smooth, then cool at room temperature.

In a large mixing bowl, beat egg whites with an electric mixer until foamy. Continue beating and slowly add 1/2 cup sugar, 1 tablespoon at a time. Beat just until soft peaks form when beaters are lifted, but whites are not stiff, about 3 to 5 minutes.

In another large mixing bowl, whisk egg yolks with remaining 1/4 cup sugar just until blended. Slowly whisk in lukewarm chocolate mixture, orange peel, 1-1/2 tsp vanilla and salt. To lighten batter, using a spatula, gently but thoroughly stir 1/4 of whites into chocolate mixture. Then, gently fold in remaining egg whites just until streaks of egg white disappear. Pour batter into pan and smooth top.

Bake in center of oven until cake is puffed and cracked, and centre no longer wobbles when pan is given a gentle shake, about 50 minutes. Do not over-bake. Run sharp edge of a knife around edge of pan to loosen cake. Leave sides on pan and refrigerate, uncovered, until chilled, at least 2 hours. Covered, cake can be refrigerated for up to 2 days.

Because whipped cream does not hold well, fill center of cake when almost ready to serve. It should then hold in the refrigerator for up to 2 hours. In a large mixing bowl, using an electric mixer, whip cream with Grand Marnier and 1 tsp vanilla until thick soft peaks form when beaters are lifted. With a wet knife, loosen cake again from sides of pan. Remove sides. Pile whipped cream into “crater” of cake and, if you wish, lightly sprinkle with cocoa powder sifted through a small strainer or chocolate shavings. Decorate with fresh berries and mint leaves.