1. Preheat oven to 350°F (175°C) and grease and flour two 9-inch round cake pans. Line bottoms with parchment paper.

2. In a medium bowl, whisk together flour, baking powder, baking soda, and salt.

3. In a small bowl, toss blueberries with 1 tablespoon of the dry flour mixture to prevent sinking.

4. In a large mixing bowl, whisk together sugar and eggs until light and fluffy, about 2-3 minutes.

5. Slowly add vegetable oil while continuing to whisk.

6. Add buttermilk, lemon zest, lemon juice, and vanilla extract. Mix until well combined.

7. Gradually add dry ingredients to wet ingredients, mixing on low speed or by hand until just combined.

8. Gently fold in the flour-coated blueberries.

9. Divide the batter evenly between the prepared pans and smooth the tops.

10. Bake for 30–35 minutes or until a toothpick inserted in the center comes out clean.

11. Let cakes cool in pans for 15 minutes, then invert onto a wire rack and cool completely.

12. To make frosting, beat softened cream cheese and butter together until smooth and creamy.

13. Add sifted powdered sugar one cup at a time, beating on low speed until incorporated.

14. Add lemon juice and vanilla extract, then beat on medium-high until fluffy.

15. Place one cake layer on a serving plate and spread a generous layer of frosting on top.

16. Add the second layer and frost the top and sides of the cake.

17. Garnish with fresh blueberries and lemon zest if desired. Chill cake slightly before serving for clean slices.