Preheat your oven to 350°F (175°C). Grease and flour a 9-inch round cake pan to prevent sticking.

In a large mixing bowl, whisk together the ricotta cheese, sugar, and eggs until smooth and creamy.

Sift the flour and baking powder into the ricotta mixture. Gently fold to combine. Avoid overmixing to maintain a light texture.

Add the chopped pistachios, lemon zest, and vanilla extract. Stir until evenly distributed throughout the batter.

Pour the batter into the prepared cake pan and smooth the top with a spatula. Bake for 35-40 minutes, or until a toothpick inserted into the center comes out clean.

Allow the cake to cool in the pan for 10 minutes, then transfer it to a wire rack to cool completely.

Before serving, dust the cake with powdered sugar or drizzle it with honey. You can also top it with fresh berries for added color and flavor.