Creating this Lemon Blueberry Sheet Cake is a straightforward process that results in a delicious masterpiece. Follow these simple steps:

1. Preheat the Oven: Preheat your oven to 350°F (175°C) and grease a 9×13 inch baking dish.

2. Combine Dry Ingredients: In a medium bowl, whisk together the flour, baking powder, baking soda, and salt. Set this aside.

3. Cream Butter and Sugar: In a large mixing bowl, beat the softened butter with the granulated sugar until light and fluffy.

4. Mix Wet Ingredients: Add the eggs, buttermilk, lemon zest, lemon juice, and vanilla extract to the butter mixture. Beat well until completely mixed.

5. Combine Mixtures: Gradually add the dry ingredients to the wet ingredients, mixing until just combined. Be careful not to overmix which can lead to a denser cake.

6. Fold in Blueberries: Gently fold in the blueberries using a spatula or wooden spoon, ensuring they are evenly distributed without crushing them.

7. Transfer to Baking Dish: Pour the batter into the prepared baking dish and spread it evenly.

8. Bake the Cake: Place it in the preheated oven and bake for about 25-30 minutes or until a toothpick inserted in the center comes out clean.

9. Cool the Cake: Once baked, remove the cake from the oven and let it cool in the pan for 15-20 minutes before transferring it to a wire rack to cool completely.

10. Dust with Sugar (Optional): Before serving, dust the top with powdered sugar for an elegant finishing touch.