In a medium saucepan over medium heat, combine 2 cups of raspberries and 1 cup of water. Mash the raspberries gently for about 3-4 minutes to release their juices.

Strain the mixture through a fine mesh sieve into a bowl, discarding solids. Return the clear juice to the saucepan, add 1 cup of granulated sugar and 2 tablespoons of lemon juice, and bring to a boil for about 5 minutes until slightly thickened.

Allow the raspberry syrup to cool completely in the refrigerator.

Using a stand mixer fitted with a whisk attachment, pour 1 cup of heavy cream into the bowl. Beat on medium-high speed until stiff peaks form, about 4-5 minutes.

In the same mixing bowl, combine 1 cup of mascarpone cheese, ½ cup of granulated sugar, and ¼ cup of the cooled raspberry syrup. Beat on medium speed until smooth, about 2-3 minutes.

Fold in half of the whipped cream, then add the remaining whipped cream and gently fold until completely integrated.

Dip each ladyfinger into the cooled raspberry syrup for just 1-2 seconds, then arrange in a layer in an 8x8 inch dish.

Spread half of the mascarpone filling evenly over the ladyfingers, smoothing it out, and sprinkle grated white chocolate on top.

Add another layer of syrup-soaked ladyfingers, then top with the remaining mascarpone filling.

Cover tightly with plastic wrap and refrigerate for at least 6 hours or overnight for better flavor.