Preheat your oven to 350°F (180°C) and grease a 9×13 inch cake pan.

In a medium bowl, sift together the cake flour, baking powder, baking soda, and salt, then set it aside.

In another bowl, combine the buttermilk and lemon juice, letting it thicken slightly.

In a large mixing bowl, cream the butter, granulated sugar, and lemon zest until light and fluffy.

Add in the vanilla extract and eggs one at a time, making sure to scrape the bowl after each addition.

With the mixer on low, alternate adding the dry ingredients and the buttermilk mixture until everything is well blended.

Gently fold in the blueberries to keep them intact.

Pour the batter into the prepared pan and bake for 30-35 minutes, or until a toothpick comes out clean from the center.

Once baked, let the cake cool in the pan for a few minutes before transferring it to a wire rack to cool completely.

To prepare the frosting, beat the butter, cream cheese, and lemon juice together.

Gradually add powdered sugar and whipping cream until you have a smooth, creamy consistency.

Once the cake is fully cool, frost generously and serve!