In a small bowl, combine raspberries, sugar, preserves, and water. Mash slightly and set aside.
In a large bowl, beat mascarpone, cream cheese, powdered sugar, and vanilla until smooth.
Gradually mix in the melted white chocolate until well combined.
In a separate bowl, whip the heavy cream until stiff peaks form.
Fold the whipped cream into the white chocolate mascarpone mixture until fully incorporated.
Line the bottom of a 9x9-inch baking dish with ladyfingers.
Spread half of the raspberry mixture over the ladyfingers.
Top with half of the white chocolate mascarpone cream.
Repeat layers with remaining ladyfingers, raspberry mixture, and cream.
Cover and refrigerate for at least 6 hours or overnight.
Before serving, garnish with fresh raspberries and white chocolate shavings if desired.