Silky Chocolate Genoise with Raspberry Chocolate Glaze

Preheat the oven to 350°F. Butter a 9-inch spring form pan and line the bottom with a buttered sheet of parchment paper. Wrap the outside of the pan with foil to seal completely.

In a heavy saucepan over low heat, melt the semisweet chocolate and butter, stirring until smooth. Remove the pan from the heat and cool to lukewarm, stirring often.

In a large bowl, beat the egg yolks and 6 tablespoons of sugar with an electric mixer until the yolks are very thick and pale, about 3 minutes. Fold the melted chocolate and butter into the yolks and add the vanilla. Using clean, dry beaters, beat the egg whites in a medium, deep bowl until soft peaks form. Gradually add the remaining 6 tablespoons of sugar to the egg whites, beating until medium-firm peaks form.

Fold the egg whites into the chocolate batter in 3 batches. Pour the batter into the prepared spring form pan and bake for 50 minutes. The top of the cake will be puffed and cracked and a toothpick inserted into the middle of the cake will have a few moist crumbs when the cake is done.

Place the cake on a wire rack to cool and gently press down on the top of the cake to flatten it evenly. Using a small knife, slide the blade between the rim of the pan and the sides of the cake to loosen. Let the cake cool and remove the pan rim. Place a sheet of waxed paper or foil under a cake rack and invert the cake onto the rack. Remove the parchment paper from the cake.

Prepare the glaze by combining the cream and the corn syrup in a medium saucepan. Heat to a simmer and remove from the heat. Add the chocolate and raspberries and whisk until melted. Carefully pour the glaze through a large strainer to remove the raspberry seeds.

Spread 1/2 cup of the glaze smoothly over the top and sides of the cake. Freeze the cake on the rack, uncovered, for about 3 minutes to set the glaze. Pour the remaining glaze over the cake and smooth the sides and top with a spatula. Chill the cake again until the glaze is firm.