Preheat your oven to 325°F (165°C).

Ensure your tube pan is ungreased and has a removable bottom.

In a food processor, pulse 1 1/2 cups of shelled pistachios with 1/2 cup of granulated sugar until finely ground. For a smoother texture, strain the mixture through a fine-mesh sieve.

In a large mixing bowl, whisk together the ground pistachios, 2 cups of all-purpose flour, 1 tablespoon of baking powder, and 1/2 teaspoon of salt.

In another bowl, whisk together 7 large egg yolks, 3/4 cup of water, 1/2 cup of vegetable oil, and 1 teaspoon of vanilla extract until smooth.

Gradually fold the dry ingredients into the wet ingredients using a spatula. Mix until just combined—be careful not to overmix.

In a clean, grease-free bowl, whip 7 large egg whites and 1/2 teaspoon of cream of tartar with a hand mixer or stand mixer until frothy.

Gradually add 1 1/4 cups of granulated sugar and continue whipping until stiff peaks form.

Gently fold the whipped egg whites into the batter in three batches. Use a spatula and fold gently to maintain the airy texture.

Pour the batter into the ungreased tube pan and smooth the top with a spatula.

Bake for 45 minutes, or until a toothpick inserted into the center comes out clean.

Immediately invert the pan onto a cooling rack and let the cake cool completely. This step is crucial for maintaining the cake’s height.

Once cooled, run a thin knife around the edges of the pan to loosen the cake. Remove the cake from the pan and transfer it to a serving plate.

Dust the cake with powdered sugar and garnish with chopped pistachios before serving.