Cut half of the strawberries into quarters and toss them gently with balsamic vinegar and sugar then chill in the fridge.
Prepare strong espresso using a moka pot, then stir in sugar, vanilla, and rum flavoring and allow to cool to room temperature.
Blend mascarpone with half of the cooled espresso mixture in a stand mixer until smooth.
Place one wafer on a serving plate and spread Nutella evenly to the edges.
Top with another wafer, pressing gently to secure.
Spread rose preserves over the next wafer and layer it on top, pressing firmly.
Cover this with the mascarpone mixture and arrange the macerated strawberries in a circular pattern on the mascarpone.
Add the last wafer carefully on top, pressing it lightly to avoid crushing the strawberries.
Brush the top wafer with the remaining espresso mixture.
Refrigerate the assembled tiramisu for at least four hours to set.
Whip the heavy cream with sugar just before serving until stiff peaks form.
Put the whipped cream in a piping bag fitted with a star nozzle and pipe it around the edge of the tiramisu.
Place whole strawberries in the center among the whipped cream and pipe more cream over them creating a decorative pattern.
Dust the finished dessert with cocoa powder before serving.
