Purée 250g of strawberries with 2 tablespoons of sugar and the lemon juice until smooth, then strain into a shallow bowl.

Slice the remaining 250g of strawberries into thin pieces.

In a large bowl, whisk egg yolks with 50g of sugar until pale and thick, then fold in the mascarpone and vanilla extract until smooth.

In a separate clean bowl, whisk egg whites with the remaining sugar until stiff peaks form, then gently fold into the mascarpone mixture.

Briefly dip each ladyfinger into the strawberry purée mixture, ensuring they are moistened but not soaked through.

Arrange a single layer of dipped ladyfingers in the bottom of a rectangular serving dish.

Spread half of the mascarpone cream over the ladyfingers and layer half of the sliced strawberries on top.

Add a second layer of dipped ladyfingers and top with the remaining mascarpone cream.

Cover and refrigerate for at least 4 hours, ideally overnight, and garnish with remaining sliced strawberries before serving.