Preheat oven to 350°F (175°C) and grease a 9-inch round baking dish with butter or cooking spray.
In a large mixing bowl, whisk together the ricotta cheese, eggs, sugar, lemon zest, lemon juice, and vanilla extract until smooth.
Sift the flour, baking powder, and salt into the ricotta mixture and stir until just combined.
Gently fold in 3/4 cup of the blueberries.
Pour the batter into the prepared baking dish and sprinkle the remaining 1/4 cup of blueberries over the top.
Bake for 30 to 35 minutes, or until the edges are golden brown and the center is set but still slightly jiggly.
Allow the bake to cool for 10 minutes before serving.