Preheat the oven to 160° C fan.
Line the loaf tin w/ baking parchment crosswise.
Mix flour, baking powder, cocoa and salt.
Whip the eggs & the sugar w/ your electric handheld mixer; add the olive oil, the milk & the vanilla extract.
Add the flour mix & mix until there's a smooth mess.
Add the chopped pistachios & mix - if you like.
Fill the dough in the loaf tin & let it bake in the preheated oven for about 40 - 50 min.
After 40 min make the famous test w/ the wooden pin ... & decide if to prolong the oven session by 5 or 10 min or whatever.
Let the cake rest in the loaf tin for about 10 - 15 min; then lift it onto a cooling rack.