Preheat your oven to 350ºF (177ºC) and prepare three 8-inch round cake pans with non-stick spray and parchment.

In a mixing bowl, whisk 3 cups of all-purpose flour, 2 teaspoons of baking powder, 1 teaspoon of baking soda, and 1 teaspoon of salt. Set aside.

Combine 1 cup of whole milk with 2 tablespoons of lemon juice in a measuring cup, stir, and let sit for 5 minutes.

In another bowl, cream together 1 ½ cups of granulated sugar and the zest of 2 lemons, then beat in ½ cup of unsalted butter until fluffy.

Add ½ cup of vegetable oil, then mix in 3 large eggs one at a time, followed by 1 teaspoon of vanilla extract.

Alternate adding the dry mixture and lemon milk mixture to the bowl, mixing until just combined.

Coat 1 ½ cups of halved blueberries with 1 tablespoon of flour and gently fold into the batter.

Divide the batter among the prepared pans and bake for 30-35 minutes or until a toothpick comes out clean.

Allow to cool in the pans for 10 minutes before transferring to a wire rack to cool completely.

For the buttercream, beat together 1 cup of cream cheese and ½ cup of butter, then mix in 4 cups of powdered sugar and 2 tablespoons of lemon juice until fluffy.

Once cooled, level the cake layers and frost with buttercream accordingly.

Garnish with fresh blueberries and lemon slices if desired.