Prepare Raspberry Jam: In a medium saucepan over medium heat, combine frozen raspberries, 100g of granulated sugar, and the juice of half a lemon. Stir frequently for about 23-25 minutes until thickened.

Make Raspberry Syrup: In a separate saucepan, combine 100g of granulated sugar, 120g of water, and additional raspberries. Simmer over medium heat for about 3 minutes.

Create Mascarpone Filling: In a large bowl, beat together mascarpone cheese, 200g powdered sugar, lemon juice, and vanilla paste until smooth. Gradually add cold heavy cream until medium-stiff peaks form.

Assemble Tiramisu: Spread a layer of mascarpone in the bottom of a dish, dip ladyfinger cookies quickly in raspberry syrup, layer them, and add half of the raspberry jam followed by another layer of mascarpone.

Chill and Set: Cover the assembled Tiramisu with plastic wrap and refrigerate overnight.

Serve with Elegance: Spread remaining raspberry jam on top, decorate with fresh raspberries and lemon slices, and serve chilled.