Preheat your oven to 340°F (170°C). Grease a 9-inch springform pan and line the bottom with parchment paper.
In a double boiler, melt the dark chocolate until smooth. Set aside to cool slightly.
5.3 oz high-quality dark chocolate (70% cacao)
In a large bowl, beat the softened butter and half of the sugar (1/4 cup) until pale and fluffy. Add the melted chocolate and vanilla extract, mixing well. Add the egg yolks one at a time, beating after each addition.
11 tbsp unsalted butter, 1/2 cup granulated sugar, 1 tsp vanilla extract, 6 large eggs
In a separate bowl, beat the egg whites with a pinch of salt until soft peaks form. Gradually add the remaining sugar (1/4 cup) and continue beating until stiff peaks form.
pinch of salt
Gently fold the whipped egg whites into the chocolate mixture. Sift in the all-purpose flour and almond flour, folding gently to combine.
3/4 cup all-purpose flour, 1/2 cup almond flour
Pour the batter into the prepared pan and smooth the top. Bake for 50-60 minutes or until a skewer inserted into the center comes out clean. Let the cake cool completely before removing from the pan.
In a small saucepan, heat the apricot jam with 2 tablespoons of water until smooth. Slice the cake horizontally into two layers. Spread a generous layer of the warmed apricot jam on the bottom layer, then place the top layer back on. Brush the top and sides of the cake with the remaining jam.
2/3 cup apricot jam, 2 tbsp water
In a saucepan, bring the granulated sugar and water to a boil, simmering for about 5 minutes. Remove from heat and stir in the chopped dark chocolate until melted and glossy.
1 cup granulated sugar, 1/2 cup water, 5.3 oz dark chocolate
Place the cake on a wire rack over a baking sheet. Pour the warm chocolate glaze over the cake, ensuring it covers the top and sides evenly. Let the glaze set at room temperature.