Whip the Cream: In a large mixing bowl, pour in 300ml of double cream along with 75g of icing sugar. Using a hand mixer or a whisk, whip the mixture until it reaches soft peaks, which should take about 2-4 minutes. The cream should be thick enough to hold a shape but still smooth for folding later. Set aside once completed.

Combine the Creams: In a separate bowl, blend together 250g of mascarpone and 100g of pistachio cream until well mixed. Gently fold this mixture into the whipped cream, being careful to maintain the airy texture.

Soak the Lady Fingers: Prepare a shallow dish with strong coffee, allowing it to cool slightly. Quickly dip each 200g of savoiardi sponge fingers in the coffee for just 2-3 seconds on each side, ensuring they are soaked but not soggy. Arrange the soaked lady fingers in a single layer at the base of your serving dish.

Layer the Cream Mixture: Spread half of the pistachio cream mixture evenly over the layer of coffee-soaked lady fingers, smoothing it out with a spatula.

Repeat the Layering: Repeat the soaking process for the remaining savoiardi sponge fingers and place them on top of the pistachio cream layer. Follow this with the remaining pistachio cream mixture, spreading it out evenly.

Decorate the Tiramisu: Use the extra pistachio cream to pipe decorative swirls on top of the final cream layer.

Chill and Serve: Cover the Pistachio Tiramisu with cling film and refrigerate for at least 6 hours, though overnight is preferable. Before serving, remove it from the fridge and allow it to sit for about 20 minutes. Finally, garnish with chopped pistachios.