Chocolate Chestnut Cake

8 - 10 servings. Position a rack in the centre of the oven and preheat to 350F/180C. Butter the bottom and sides of a 9 x 2 inch round cake pan. Line the bottom with a circle of baking parchment or waxed paper and butter the paper. Melt the chocolate with the kirsch in a bowl over hot (not boiling) water. Transfer the chocolate mixture to a large bowl. Using an electric mixer set at medium speed, beat the chestnut puree into the chocolate mixture just until blended. The mixture will look lumpy. One at a time, beat in the egg yolks, beating well after each addition. Scrape down the sides of the bowl with a rubber spatula. Beat in the vanilla. One tablespoon at a time, beat in the butter, making sure each addition is fully incorporated before adding the next. Add the flour and salt and mix on low speed just until the mixture is smooth. In a grease-free large bowl, using an electric mixer, beat the egg whites at low speed until frothy. Gradually increase the speed to high and beat the whites until they form soft peaks. While continuing to beat, gradually add the sugar one teaspoon at a time. Beat the whites until they form stiff, shiny peaks. Fold one third of the whites into the chocolate mixture to lighten it. Fold in the remaining whites. Scrape the batter into the prepared pan and smooth the top with the back of a spoon. Bake the cake for 20 to 30 minutes, until a wooden toothpick inserted 1 inch from the side of the pan comes out clean; the centre of the cake will remain soft and creamy. Do not overbake. Set the cake in the pan on a wire rack to cool for 1 hour. When the cake is completely cool, invert it onto an 8.5 inch cardboard cake circle and peel off the paper circle. Wrap the cake in plastic wrap and refrigerate overnight. Put the chocoate in a 1 quart measuring cup with a pouring spout. In a small saucepan, set over medium heat, heat the cream and corn syrup, stirring constantly with a wooden spoon, until the mixture comes to a boil. Pour the hot cream over the chocolate. Let the mixture stand for 30 seconds to melt the chocolate. Gently whisk until smooth. Stir in the vanilla. Unwrap the chilled cake and put it (still on the cardboard circle) on a wire rack. Set the wire rack with the cake over a baking sheet. Pour the warm chocolate glaze over the cake, coating it completely. Gently tap the wire rack several times to remove any excess glaze. Use the end of a pin to pop any unsightly air bubbles. Put the baking sheet with the cake in the refrigerator and chill for 5 to 10 minutes to set the glaze. Using two long metal cake spatulas, transfer the cake to a plate. Cut the cake while it is still chilled with a hot knife. Rinse the knife blade between slices. Transfer the cake slices to dessert plates. If desired, garnish the top of each piece of cake with a sprinkling of white chocolate curls. Let the cake slices stand at room temperature for 20 minutes before serving. You can even dust the plate with some cocoa and serve a few marrons glaces on the side.