Preheat the oven to 350°F. Line three 9-inch round cake pans with parchment paper circles. Spray the cake pans with bakers spray (Baker’s Joy or a generic version)

Add 3 cups of flour, baking powder, baking soda, and kosher salt to a medium-sized mixing bowl. Whisk to combine.

Add the fresh lemon zest to the granulated sugar to a small bowl. Stir to combine.

Add the blueberries to a medium-sized mixing bowl. Sprinkle with 2 tablespoons of flour. Stir to coat the blueberries completely. Remove the excess flour.

Using a stand mixer or a large mixing bowl and a handheld mixer on medium-high speed, beat together the softened butter and vegetable oil for 1 minute or until well incorporated.

Add the buttermilk, fresh lemon juice, and vanilla. Mix just until combined. (The mixture will appear curdled, but it has a lot of acidity due to the lemon juice and buttermilk.)

Add the eggs, one at a time, beating well after each.

Add ½ of the flour mixture, mixing just until combined. Repeat for the remaining flour mixture.

Using a stand mixer or a large mixing bowl and a handheld mixer on medium-high speed, beat together the softened butter and softened cream cheese for about 2 minutes or until smooth.

Beat in the lemon zest and 1 cup of powdered sugar. Alternate with adding 1 tablespoon of half and half and 1 cup of powdered sugar at a time. Continue mixing until smooth.

Place the first layer of cake on either a disposable round cake board or a serving plate. Top with ¾ cup of frosting. Use an offset spatula to smooth the frosting to the edge of the first layer of the cake. Repeat with the remaining layers of cake. Next, smooth the remaining frosting over the top and sides of the cake until the entire cake is frosted. Garnish the center of the frosted top with remaining blueberries and thinly sliced lemons. Slice and serve.