Begin by setting up a double boiler: fill a saucepan with water and bring it to a gentle simmer. Place a heatproof bowl on top, ensuring it doesn’t touch the water. Add 200g of dark chocolate to the bowl and stir occasionally until melted and smooth. Remove from heat and let it cool to room temperature while you prepare the other components.

In a mixing bowl, combine 4 large eggs and 100g of caster sugar. Using an electric whisk, beat the mixture until it becomes pale, fluffy, and thickened—this usually takes about 5 minutes on medium speed.

In another medium bowl, pour 300ml of double cream and begin to whip it using a hand mixer until you reach soft peaks.

Gently fold the cooled melted chocolate into the egg mixture. Add the seeds from one vanilla pod and mix gently until combined. Next, carefully fold in the whipped cream until the mixture appears uniform and creamy.

Chop 100g of pistachio nuts roughly and fold them into the chocolate mixture.

Prepare your mold by greasing it lightly with butter or neutral oil. Pour the semifreddo mixture into the mold, smoothing the top with a spatula. Cover with plastic wrap and place it in the freezer for a minimum of 4 hours.

To serve, remove from the freezer and let it soften slightly at room temperature for about 10-15 minutes. Cut into generous pieces and drizzle with chocolate sauce or sprinkle some extra pistachios on top.