Preheat oven to 350°F (175°C). Grease and line a 22-cm cake pan.
Cream 1 cup butter with 1 cup sugar until fluffy. Add melted chocolate, then egg yolks, one at a time. Stir in 1 tsp vanilla.
Beat egg whites until stiff. Fold into chocolate mix alternately with 1 cup flour.
Pour into pan and bake for 45-50 minutes. Cool completely.
Slice cake in half horizontally. Spread 1/2 cup apricot jam between layers. Reassemble cake
Melt 7 oz (200g) of dark chocolate over a double boiler, stirring until smooth.
Remove from heat and gradually stir in 1/4 cup (60ml) of heavy cream until the glaze becomes glossy and pourable.
Pour the glaze over the top of the assembled cake, allowing it to drip down the sides. Let it set for 15 minutes before serving.
Heat 1/2 cup (120ml) of heavy cream over low heat. Add 1 tbsp of dried calendula petals and steep for 10 minutes.
Strain out the petals, chill the cream, and whip it until soft peaks form.
Spread the calendula cream over the cake or use it as a decorative topping. Garnish with fresh calendula petals for a colorful, edible finish.