1. Brew strong coffee and allow it to cool completely.

Prepare filling

1. In a large bowl, combine the mascarpone and cream cheese until smooth. Add the peanut butter and scraped vanilla bean seeds, mixing until incorporated.
2. Sift in the powdered sugar, folding gently until smooth.
3. In a separate bowl, whip the heavy cream until soft peaks form. 
4. Gently fold the whipped cream into the mascarpone mixture.

Assemble

1. Briefly dip each ladyfinger into the cooled coffee—just until moistened—and arrange a single layer in the pan.
2. Spread a thin layer of peanut butter over the ladyfingers.
3. Spread half of the mascarpone filling evenly over the peanut butter layer.
4. Add another layer of soaked ladyfingers, followed by the remaining filling. Smooth the top.
5. Cover and refrigerate for at least 6 hours, or overnight.
6. Melt the Nutella until smooth, then pour it evenly over the chilled tiramisu. Warm the peanut butter slightly, place it in a piping bag, and pipe straight lines across the surface. Drag a knife in the opposite direction to create a feathered pattern.
7. Slice with a warm knife and serve chilled.