For a silky smooth texture, make sure the chocolate, gelatin, and egg yolk mixture is still warm when folded together, before adding the cream.
a nonstick, 1 lb. loaf pan, greased and lined with 2 long strips of parchment paper so the ends hang over the 4 edges of the pan
Put the chocolate pieces in the top of a double boiler set over simmering, but not boiling, water (do not let the bottom of the pan touch the water). Melt the chocolate gently, stirring occasionally, until smooth. Remove the top pan from the heat and let the chocolate cool slightly.
Put the gelatin sheets in a small saucepan and cover with cold water. Let soak for 3 minutes until soft, then drain off the water. Heat the gelatin over very low heat, swirling the pan, until the gelatin dissolves. Set aside.
Put the egg yolks in a large heatproof bowl and beat with a hand-held electric mixer until pale and creamy.
Put the sugar and ¼ cup water in a small saucepan and heat gently until the sugar has dissolved. Increase the heat and cook for 3 minutes or until the temperature of the water has reached 240°F—check with a sugar thermometer. Gently pour the sugar syrup onto the egg yolks, beating with a hand-held electric mixer as you pour, until the mixture becomes thick and creamy Beat in the brandy if using. Add half the warm chocolate and stir well with a large metal spoon until well mixed. Gently stir in the remaining chocolate, followed by the warm gelatin.
Put the cream in a bowl and whisk until it starts to thicken. Using a large metal spoon, gently fold the cream into the chocolate mixture. Pour the mixture into the prepared loaf pan, tapping the bottom gently on the counter so the mixture reaches the corners. Level the top with a knife. Cover and chill in the refrigerator overnight until set.
When ready to serve, gently lift the marquise out of the pan by pulling upon the parchment paper and transfer to a serving plate. Dust with cocoa powder, then cut into thick slices. Serve with a drizzle of cream.
© 2005 Sara Jayne Stanes. All rights reserved.