In a medium saucepan, combine the quartered strawberries, granulated sugar, and water. Bring to a gentle simmer over medium heat, stirring occasionally.

Cook for 8-10 minutes, or until the strawberries have softened and released their juices, creating a syrupy mixture.

Remove from heat and stir in the fresh lemon juice. Allow the syrup to cool completely to room temperature. For a smoother syrup, you can mash the strawberries slightly with a fork or use an immersion blender for a few pulses.

In a large mixing bowl, combine the softened mascarpone cheese, sifted powdered sugar, vanilla extract, and salt. Mix with a rubber spatula until just smooth and no lumps remain. Be careful not to overmix, as mascarpone can curdle.

In a separate, very clean large mixing bowl, whip the very cold heavy cream with an electric mixer (or whisk by hand) on medium-high speed until stiff peaks form. This will take 3-5 minutes with an with an electric mixer.

Gently fold about one-third of the whipped cream into the mascarpone mixture to lighten it. Then, carefully fold in the remaining whipped cream until fully combined and smooth. Do not overmix.

Dip each ladyfinger briefly into the cooled strawberry syrup, ensuring it's moistened but not soggy. Place a single layer of soaked ladyfingers at the bottom of a 9x13 inch baking dish, breaking them as needed to fit.

Spread half of the mascarpone cream evenly over the layer of ladyfingers.

Arrange a generous layer of sliced fresh strawberries over the mascarpone cream.

Repeat the layers: another layer of syrup-soaked ladyfingers, followed by the remaining mascarpone cream, and finally, a top layer of sliced fresh strawberries.

Cover the dish tightly with plastic wrap and refrigerate for at least 4 hours, or preferably overnight, to allow the flavors to meld and the dessert to set.

Before serving, dust lightly with additional powdered sugar if desired. Slice and serve chilled.