Preheat your oven to 350°F and grease a 9x5-inch loaf pan, then line it with parchment paper for easy removal.
Whisk together the flour, baking powder, and salt in a medium bowl until well combined and set aside.
In a large mixing bowl, cream the softened butter and sugar with an electric mixer on medium speed for 2 to 3 minutes until the mixture is light and fluffy.
Beat in the eggs one at a time, followed by the vanilla extract, scraping down the sides of the bowl to ensure everything is fully incorporated.
Alternate adding the dry ingredients and the milk to the butter mixture, mixing on low speed just until the batter is smooth with no streaks of flour remaining.
Fold in the chopped pistachios and lemon zest with a spatula until they are evenly distributed throughout the batter.
Pour the batter into the prepared loaf pan and bake for 50 to 60 minutes, or until a toothpick inserted into the center comes out clean.
While the loaf is still warm in the pan, brush the top with the fresh lemon juice to allow it to soak in and create a moist, tangy crust.