01 - Preheat your oven to 350°F (175°C). Grease and line a 9-inch (23 cm) round cake pan with parchment paper.
02 - In a medium bowl, whisk together the all-purpose flour, baking powder, baking soda, and salt. Set this mixture aside.
03 - In a large bowl, use an electric mixer to beat the softened unsalted butter and granulated sugar until the mixture becomes light and fluffy, approximately 2 to 3 minutes.
04 - Add the eggs one at a time, ensuring each egg is thoroughly incorporated before adding the next. Mix in the ricotta cheese, vanilla extract, and lemon zest until all components are well combined.
05 - Gradually incorporate the whisked dry ingredients into the wet mixture, stirring until just combined. Be careful not to overmix the batter.
06 - Gently fold the fresh blueberries into the batter using a rubber spatula until they are evenly distributed.
07 - Pour the prepared batter into the greased and lined cake pan. Smooth the top of the batter. If desired, sprinkle the surface with turbinado sugar.
08 - Bake for 38 to 42 minutes, or until a toothpick inserted into the center of the cake comes out clean and the top appears golden brown.
09 - Allow the cake to cool in the pan for 15 minutes before carefully transferring it to a wire rack to cool completely. Slice and serve once fully cooled.