01 -
Place raspberries and water in a medium saucepan over medium-high heat. Using a potato masher or a fork, crush the berries. Bring the berries to a simmer, then lower temperature to medium-low and simmer for about 2 minutes.
02 -
Remove pan from heat and pour berries into a fine-mesh strainer set over a glass measuring cup. Using the back of a ladle or spoon, press on the berries to squeeze out as much juice as possible. Discard seeds.
03 -
Return raspberry juices to the pan, then add the sugar and lemon juice. Bring to a boil and simmer for about 4-5 minutes until mixture reduces slightly. Remove from heat and chill in refrigerator to cool completely.
04 -
In a stand mixer fitted with the whisk attachment, whip the heavy cream until stiff peaks form. Transfer whipped cream to a separate bowl, return bowl to the mixer, and replace whisk attachment with paddle attachment.
05 -
To the mixer, add the mascarpone cheese, sugar, 3/4 cup of the raspberry syrup, and vanilla. Beat on high until combined. Add about a cup of the whipped cream and continue beating until incorporated. Gently fold in the rest of the whipped cream.
06 -
One at a time, dip the ladyfingers in the raspberry syrup until soaked but not soggy; arrange in an even layer along the bottom of an 8-inch square dish. Spread half of the the mascarpone filling on top of the ladyfingers. Using a zester, microplane, or cheese grater, grate half of the white chocolate evenly on top. Place another layer of raspberry syrup-soaked ladyfingers on top of the filling.
07 -
Spread half of the remaining filling on top of the ladyfingers. Transfer remaining filling to a pastry bag fitted with a large round tip (or a gallon ziplock bag with the corner cut off), and pipe the filling evenly over the tiramisu. Grate the rest of the white chocolate on top.
08 -
Cover with plastic wrap and refrigerate for at least 6 hours, preferably overnight.