01 -
Combine frozen raspberries, granulated sugar, and lemon juice in a saucepan over medium heat. Stir occasionally as the raspberries thaw and begin to break down. Once the mixture comes to a boil, reduce to a simmer and mash the raspberries with a rubber spatula.
02 -
Simmer for 23–25 minutes until thickened. Test consistency by running a finger through jam on a spoon; if it leaves a clean line, it's ready. Transfer to a shallow bowl, cover with plastic wrap, and refrigerate to cool completely—about 1 hour.
03 -
In a small saucepan, bring granulated sugar, water, and frozen raspberries to a boil, stirring until sugar dissolves. Reduce to a simmer and cook for 3 minutes, breaking down berries. Strain syrup through a fine sieve, discard solids, stir in limoncello, and allow to cool to room temperature.
04 -
Using a mixer, combine mascarpone cheese, powdered sugar, lemon juice, and vanilla paste until smooth, about 30 seconds. Scrape bowl, then add cold heavy cream and whip until medium-stiff peaks form.
05 -
Spread a thin layer of mascarpone cream on the base of a 27x20 cm or similar sized dish. Dip each ladyfinger twice in the raspberry syrup, then arrange in a single layer over the cream.
06 -
Spread half of the mascarpone filling over the ladyfingers and smooth to an even layer. Top with half of the raspberry jam, spreading gently.
07 -
Repeat layering with another layer of dipped ladyfingers and the remaining mascarpone filling. Reserve the second half of the raspberry jam for serving.
08 -
Cover with plastic wrap and refrigerate for at least 8 hours or overnight to set.
09 -
Before serving, spread the remaining raspberry jam over the tiramisu. Decorate with fresh raspberries and lemon slices as desired.