Preheat the oven to 350°F (175°C).
Line the bottom of a springform pan with parchment paper.
Separate the eggs between two clean mixing bowls.
Add the sugar to the yolks.
Beat until pale and slightly thickened.
Mix in the oil, lemon zest, and vanilla.
Stir in the 150 g ground pistachios until evenly combined.
In the second clean bowl, beat the egg whites to stiff peaks.
Fold about one-third of the whites into the pistachio batter to lighten it.
Fold in the remaining egg whites in 1–2 additions.
Stop folding once no large white streaks remain.
Transfer the batter to the prepared pan.
Smooth the surface gently.
Sprinkle chopped pistachios over the top.
Bake at 350°F (175°C) for about 30 minutes, until set and a toothpick comes out clean or with a few moist crumbs.
Cool in the pan for approximately 30 minutes.
Release the springform sides.
Cool completely before slicing.