In a mixing bowl, combine room-temperature mascarpone with sifted powdered sugar until smooth, about 2 minutes. In a separate chilled bowl, whip heavy cream until soft peaks form, approximately 3 minutes with an electric mixer. Fold the whipped cream into the mascarpone mixture until just combined.

In a shallow dish, mix fresh orange juice and half of the orange liqueur. Quickly dip each ladyfinger in the mixture for no longer than 2 seconds. Arrange the dipped ladyfingers in a single layer at the bottom of your serving dish.

Spread half of the creamy filling over the layer of ladyfingers, then add half of the strawberry preserve, followed by half of the sliced strawberries.

Place another layer of dipped ladyfingers over the strawberries, then spread the remaining cream filling on top. Add the rest of the strawberry preserve and top with the remaining sliced strawberries.

Drizzle the leftover orange liqueur over the top, cover with plastic wrap, and refrigerate for at least 2 hours. For best results, let it chill overnight.