Make the strawberry jam

• Add the strawberries, sugar and lemon juice to a saucepan.
• Cook, stirring occasionally, until the strawberries come to a boil, then lower the heat and keep cooking until a thermometer reads between 200 and 220 °F (93–104 °C).
• Without a thermometer, stop once the jam is dark, thick and reduced. Transfer to a bowl and let it cool.

Beat the mascarpone filling

• Beat the mascarpone with powdered sugar, lemon juice and vanilla extract until combined.
• In another bowl, whip the heavy cream with powdered sugar until peaks form.
• Fold half of the whipped cream into the mascarpone, then fold in the remaining half.

Make the strawberry syrup

• Mix some of the strawberry jam with the strawberry liqueur (or juice for an alcohol-free version).

Build the first layer

• Dip each ladyfinger in the strawberry syrup and lay them side by side in the bottom of the dish.
• Top with half of the mascarpone filling and spread it evenly with an offset spatula.
• Spread about half a cup of the jam over the mascarpone and top with chopped strawberries.

Build the second layer

• Dip the remaining ladyfingers in the syrup and place them on top of the strawberries.
• Cover with the remaining mascarpone filling and smooth the surface.

Chill overnight

• Let the tiramisu set in the fridge overnight before decorating.

Decorate and serve

• Pulse the freeze-dried strawberries in a small food processor and sift the powder over the tiramisu.
• Pipe whipped cream around the edges and top with fresh strawberries.