Prepare the fruity jelly according to the package instructions, but only use half of each packet. Pour each flavor into a separate shallow dish and let set in the refrigerator for at least 2 hours.
Put the shortbread cookies, melted butter, cocoa powder, speculaas spices, and salt in a food processor and mix until a cohesive crumb mixture is formed.
Press this mixture firmly into a springform pan as the base. Place in the refrigerator.
Soak the gelatin leaves in cold water.
Heat the apple juice with the yuzu juice until lukewarm. Squeeze out the gelatin and dissolve it completely in the warm juice.
Whip the sour cream, cream cheese, cream, and fine sugar until light and fluffy. While mixing, pour in the juice mixture.
Cut the set jelly into irregular cubes and carefully fold them into the filling.
Pour the filling onto the base and smooth it out. Let set for at least 2 hours (preferably longer).
Finish with whipped cream and strawberries just before serving.
Tips
- Use a shallow dish for the jelly so you can easily cut cubes.
- Only mix the jelly at the end and fold it in carefully for a beautiful terrazzo effect.
- No yuzu? Use extra apple juice or replace with pineapple juice.
- For neat slices: place the cake in the freezer for 15 minutes before cutting.
- Optionally, garnish with extra loose jelly cubes on top.
- Storage
In the refrigerator: Covered, lasts up to 3 days.
In the freezer: Up to 1 month, without whipped cream and strawberries.