In a small saucepan, combine raspberries and water. Simmer for 5-7 minutes, strain, and return juice to saucepan. Add sugar and lemon juice, heat until thickened, then cool.

In a mixing bowl, whip heavy cream until stiff peaks form, about 3-5 minutes. Set aside.

In a separate bowl, beat mascarpone cheese, sugar, and cooled raspberry syrup until smooth. Gently fold in whipped cream.

Dip each ladyfinger in raspberry syrup quickly and arrange in the bottom of an 8-inch square dish.

Spread half of mascarpone filling over ladyfingers and grate half of white chocolate on top.

Repeat with remaining ladyfingers and mascarpone filling, finishing with grated white chocolate.

Cover with plastic wrap and chill for at least 6 hours or overnight before serving.