MOUSSE CAKE WITH JAPANESE SPONGE BISCUIT

The calculation is for a cake with a diameter of 18 cm (7 inch) and a height of 7 cm (2.8 inch).

1. **Mousse**: 1. Soak the gelatin in cold water. 2. Heat 50ml (1.70 fl oz) of the cream until warm. Be careful not to let it boil. 3. Whip the remaining cream until it reaches the consistency of thick sour cream. Add the powdered sugar and vanilla extract, continuing to whisk until combined. 4. Fold in the mascarpone and whip until the mixture is fluffy. Make sure the mascarpone is at room temperature for smoother blending. 5. Squeeze out excess water from the gelatin and mix it with the hot cream. Stir until dissolved, then let the mixture cool slightly before adding it to the mousse. 6. Divide the mousse into two equal parts. To one part, add the mushed blueberries; to the other part, add the rubbed sea buckthorn along with an additional 20 g (0.70 oz) of powdered sugar. 7. Place a ring mold on a Teflon mat and cover the sides with acetate foil. 8. Cut out two strips of the Japanese sponge biscuit to fit the circumference of the ring and a 16 cm (6.3 inch) round piece for the bottom. 9. Line the sides of the mold with the biscuit strips and insert the bottom piece. 10. Pour the blueberry mousse into the mold and freeze for 10-15 minutes. Freezing helps create neat, distinct layers. 11. Mix the blackberries into the sea buckthorn mousse and pour it over the set blueberry mousse. 12. Place the cake in the fridge for a few hours to set completely. 13. Decorate the cake with mint and berries before serving.

2. **Japanese Sponge Biscuit**: 1. Mix the milk with the butter in a small pan and heat until almost boiling. Ensure the butter melts completely. 2. Add pre-sifted flour and stir the mixture while still on the heat until it starts to form a lump and leaves a velvety trace at the bottom of the pan. 3. If you’re making a single-color cake, add any food coloring now and stir until the dough cools down to 40-45°C (104-113°F). If using multiple colors, cool the dough to this temperature without adding coloring yet. 4. Add the eggs and yolks one at a time, mixing thoroughly after each addition. 5. Whip egg whites with a pinch of salt until they form a strong foam. Gradually add sugar and continue to whip until firm peaks form. 6. Gently fold the whipped egg whites into the dough mixture at the lowest mixer speed or by hand with a spatula. 7. Set aside 1/2 cup of dough and color it yellow, then place it into a pastry bag. Color the remaining dough purple. 8. Preheat the oven to 170°C (338°F). 9. Place a Teflon mat on a 36 x 30 cm (14.2 x 11.8 inch) baking sheet. Pipe yellow circles onto the mat, then carefully spread the purple dough over the circles, smoothing it out. 10. Bake the sponge for 15-17 minutes, but do not allow it to brown. 11. Slightly cool the sponge cake, then wrap it in foil to retain softness. Remove the Teflon mat and tightly cover the other side with film again. Use the bottom of the biscuit for decorating and trimming as needed.