First prepare the choux pastry: melt the butter with the water in a thick-bottomed pan, then incorporate the flour all at once, stirring vigorously with a wooden spoon until the mixture begins to detach from the walls.
At that point, remove from the heat and leave to cool, then incorporate the eggs 1 at a time, without adding the second until the first is completely incorporated, then transfer the mixture into a piping bag with a not too thin star-shaped nozzle.

Create the zeppole on the baking tray lined with baking paper, not too large (7-8 cm in diameter) and well spaced between them, and cook in a preheated ventilated oven at 200°C for 10 minutes, then lower the temperature to 180 °C and cook for another 15-20 minutes, finally remove from the oven and leave to cool completely.

When the zeppole are now cold, prepare the filling: mix the mascarpone and pistachio cream with an electric whisk, then add half the cream and whip again until you obtain a puffy and homogeneous frosting.

Transfer the frosting into a clean piping bag, still with the star nozzle, cut the zeppole in half horizontally and fill them.

Finally, whip the remaining cream and decorate the zeppole with a dollop of cream and a little chopped pistachios.

The San Giuseppe zeppole with pistachio are ready, all you have to do is enjoy them.