Stir the cherries with the cherry juice and the sugar and let it bubble up once. Stir the cornstarch with a little cold water, add it to the cherries and let it boil up while stirring. Cool the cherry compote.
In the meantime, mix the vanilla sauce with mascarpone and vanilla sugar until smooth. Spread half of the amount in a sufficiently large bowl or mold. Soak the sponge cake with the amaretto and place it on the mascarpone layer. Spread the cooled cherry compote evenly on top.
Using a piping bag with a star-shaped nozzle, pipe the remaining mascarpone cream onto the compote in a grid pattern.
Chill the dessert in the refrigerator for at least 30 minutes.
If the dessert is to be eaten by children as well, the sponge cake should not be soaked with amaretto but with a strong cocoa.