The Chocolate Mousse Cake combines delicate milk and dark chocolate mousse with a fruity apricot layer and a very thin shortcrust base. Dark chocolate ganache and white chocolate shavings complete the cake.
Line the base of a 24 cm / about 9.5-inch springform pan with parchment paper. Preheat the oven to 175 °C / 350 °F using a conventional, non-fan oven setting. Mix the flour, sugar, baking powder, and salt. Quickly work in the cold sunflower margarine with your fingertips until fine crumbs form. Carefully separate the egg. Add the egg yolk and briefly bring everything together into a smooth dough. Add up to 1 tsp cold water only if needed. Spread the dough evenly over the base of the pan and press it down to a thickness of about 2.5–3 mm / about 1/8 inch using the flat bottom of a glass. Do not form a raised edge. Prick the base several times with a fork and chill for 10 minutes.
Bake the shortcrust pastry base on the middle rack for 15 minutes. Remove it from the oven and immediately brush the surface with a very thin layer of egg white. Bake for another 2–5 minutes, until the very thin base is fully baked and lightly golden around the edge. Let the shortcrust pastry base cool completely on the parchment paper. Leave the parchment paper underneath the base so the delicate pastry does not need to be moved unnecessarily when the cake is assembled later.
Prepare the apricots and assemble the apricot layer
Drain the apricots very well. You will need 480 g of drained apricots. Cut the apricots into small pieces with a knife. Do not purée them. The finished layer should retain a noticeable but fine fruit texture. Whisk 40 ml of the cold apricot juice with the cornstarch until completely smooth. Heat the remaining 40 ml apricot juice with the apricots and sugar in a saucepan. Stir in the apricot jam, lemon juice, and cinnamon. Add the cornstarch mixture while stirring. Bring the apricot mixture to a full boil and continue cooking for about 1 minute, stirring gently, until it thickens noticeably. The finished mixture should still be easy to spread but should no longer run. If you draw a line through the mixture with a spoon, the line should mostly remain visible. Let the apricot mixture cool for about 15–20 minutes.
Lightly brush the inside of the cake ring with rapeseed oil. Line the inside of the ring smoothly with a strip of coated parchment paper or cake collar acetate that is tall enough to cover the inside of the ring. Place the fully cooled shortcrust pastry base, still on its parchment paper, onto the cake plate and fit the prepared cake ring snugly around the base. Spread the apricot mixture evenly over the shortcrust pastry base and gently smooth the surface. Let the apricot layer cool completely, then refrigerate for at least 45 minutes. Before adding the mousse, the fruit layer must be completely cold and firm.
Prepare the chocolate, whipping cream, and meringue
Finely chop the dark chocolate couverture and milk chocolate couverture and place them together in a bowl. Gently melt the chocolate over a warm water bath. Remove the bowl from the water bath and let the chocolate mixture cool slightly, stirring occasionally. It should still be completely smooth and flow easily, but it should no longer be hot.
Using an electric hand mixer, whip the whipping cream until thickened and creamy. It should form soft peaks and still be smooth and flexible. Do not whip it until fully stiff. Begin beating the egg whites with the pinch of salt. Gradually add the 150 g sugar and continue beating until the meringue is firm, fine-textured, and glossy. It should form firm peaks but should not become dry or grainy.
Finish the chocolate mousse and prepare the decoration
Quickly whisk about one third of the whipped cream into the still-fluid chocolate mixture. This makes the chocolate base lighter and smoother. Gently fold in the remaining whipped cream in two portions using a silicone scraper. Next, carefully fold about one third of the whipped egg whites into the chocolate-cream mixture. Fold in the remaining egg whites in two portions. Use the silicone scraper to lift the mixture from the bottom of the bowl upward, mixing only until no larger white streaks remain. The finished mousse should be creamy and airy while already holding some structure. It should not be runny. The chocolate shavings for the decoration can now be prepared. Use a vegetable peeler to shave thin pieces from the white chocolate. Try to make the shavings as even as possible.
Immediately spoon the chocolate mousse onto the fully chilled apricot layer. First spread the mousse around the outer edge, then fill in the center. This helps reduce air pockets along the edge of the cake. Gently smooth the surface. The mousse layer should be about 4 cm / 1.6 inches high. Refrigerate the cake for at least 6 hours, preferably overnight, until completely chilled and set. Keep the cake ring in place during this time.
Prepare and apply the dark chocolate ganache
Finely chop the dark chocolate couverture and melt it gently. Heat the whipping cream separately until hot, but do not let it boil vigorously. Add the warm cream to the melted chocolate in several portions, stirring thoroughly from the center outward after each addition. Continue stirring until the ganache is completely smooth and homogeneous. Let the ganache cool briefly. It should still flow easily and be easy to pour and spread, but it should no longer be hot.
Leave the fully chilled cake in the cake ring. Pour the ganache onto the center of the mousse and spread it evenly over the surface. Let the ganache mostly level itself, or gently texture the surface with the back of a spoon. The ganache layer should be about 3 mm / 1/8 inch thick. Refrigerate the cake for at least 1 hour, until the ganache is set.
Finish the cake
Carefully loosen and remove the cake ring, then slowly peel away the coated parchment strip or cake collar acetate. If the parchment paper underneath the shortcrust pastry base extends beyond the edge of the cake, carefully place the fully chilled cake on an elevated support and trim only the visible overhanging parchment flush with the edge. Leave the parchment paper underneath the base in place. Scatter the prepared white chocolate shavings over the ganache as desired. Keep the cake refrigerated until ready to serve. For clean slices, dip a long knife into hot water, dry it completely, and cut straight down through the cake. Clean and rewarm the knife after each slice. Remove the cake from the refrigerator about 10–15 minutes before serving.
Notizen
Shortcrust pastry baseThe very thin shortcrust pastry base is fully baked before assembly because the cake does not return to the oven afterward. The thin egg white coating also helps protect the base from moisture from the apricot layer. Leave the parchment paper underneath during assembly so the delicate base does not need to be moved unnecessarily.Apricot layerThe apricot layer must be fully cooled and firm before the mousse is added. Once set, it forms an even, stable fruit layer that provides a secure base for the chocolate mousse.NoteThe mousse contains raw egg whites. Use fresh, undamaged eggs and keep the cake refrigerated.