Preheat your oven to 350°F (175°C). Grease and flour the 9x13 inch baking pan to prevent sticking.
In a large mixing bowl, cream together the softened butter and granulated sugar using an electric mixer until light and fluffy.
Add the eggs, lemon zest, lemon juice, and vanilla extract to the butter mixture. Mix until well combined.
In another bowl, whisk together the flour, baking powder, baking soda, and salt.
Gradually add the dry ingredients to the wet ingredients, mixing just until combined. Avoid over-mixing.
Gently fold in the fresh blueberries using a rubber spatula until evenly distributed in the batter.
Pour the batter into the prepared baking pan, spreading it out evenly.
Bake in the preheated oven for about 40 minutes, or until a toothpick inserted in the center comes out clean.
Once done, remove the cake from the oven and let it cool in the pan for 10 minutes before transferring it to a cooling rack to cool completely.
Serve the Lemon Blueberry Cake sliced and enjoy!