Preheat the oven to 350°F (175°C). Grease a 9-inch (23 cm) springform and line it with parchment paper.

Melt the dark chocolate in a heatproof bowl over simmering water until smooth and glossy. Remove from heat to cool slightly.

In a large bowl, beat the softened butter with half a cup of sugar until light and fluffy (about 3-5 minutes).

Add the egg yolks one at a time, mixing well after each addition. Stir in the melted chocolate and vanilla.

In a separate clean bowl, beat the egg whites with a pinch of salt until foamy. Gradually add the remaining ¼ cup of sugar until stiff peaks form.

Gently fold the egg whites into the chocolate mixture in 2-3 portions. Then sift in the flour and fold gently until combined.

Pour the batter into the prepared pan and smooth the surface. Bake for 45-50 minutes, or until a toothpick comes out clean.

Allow the cake to cool in the pan for about 10 minutes before transferring to a wire rack.

Once cooled, slice the cake horizontally in half. Spread half of the warm apricot jam in the middle and place the top layer back on.

Spread the remaining jam over the top and sides of the cake.

For the glaze, heat the cream until it simmers, remove from heat, add chocolate, and stir until smooth.

Place the cake on a rack over a tray and pour the glaze over it, allowing it to set.