Chocolate Brownie Cake
4 1-ounce squares unsweetened chocolate
¾ cup (1½ sticks) butter
2 cups sugar
1 teaspoon vanilla extract
1 ½ cups flour
1 teaspoon baking powder
1 cup walnuts, chopped
FOR THE TOPPING
1½ cups whipping cream
8 1-ounce squares semisweet chocolate
1 tablespoon vegetable oil
1. Preheat the oven to 350°F. Line 2 8-inch cake pans with wax paper and grease the paper.
2. Melt the chocolate and butter together in the top of a double boiler, or in a heatproof bowl set over a saucepan of hot water.
3. Transfer to a mixing bowl and stir in the sugar. Add the eggs and vanilla and mix until well blended.
4. Sift over the flour and baking powder. Stir in the walnuts.
5. Divide the batter between the prepared pans and spread level.
6. Bake until a cake tester inserted in the centre comes out clean, about 30 minutes. Let stand 10 minutes, then unmold and transfer to a rack.
7. When the cakes are cool, whip the cream until firm. With a long serrated knife, carefully slice each cake in half horizontally.
8. Sandwich the layers with some of the whipped cream and spread the remainder over the top of the cake. Refrigerate until needed.
9. For the chocolate curls, melt the chocolate and oil in the top of a double boiler or a bowl set over hot water. Transfer to a nonporous surface. Spread to a ⅜-inch thick rectangle. Just before the chocolate sets, hold the blade of a straight knife at an angle to the chocolate and scrape across the surface to make curls. Place on top of the cake.