Preheat oven to 350. Butter and lightly flour three 8″ round pans. Line with parchment paper circles.
Sift together 3 cups cake flour, baking powder and salt. Set aside.
In a small bowl, combine milk and lemon juice. Stir to combine and set aside for milk to curdle. This is similar to making homemade buttermilk!
In the bowl of a stand mixer, beat butter and sugar on medium-high using the paddle attachment. Beat until pale and fluffy, about 4 minutes.
With the mixer on low, add eggs one at a time. Mix well after each egg.
Add vanilla extract and lemon zest. Mix to combine.
Add the flour mixture in three batches, alternating with the milk, beginning and ending with the flour mixture. Do not over mix. Stop the mixer and scrape down the bowl.
In a small bowl, gently toss blueberries with 2 tablespoons cake flour to coat. Using a spoon or spatula, gently fold blueberries into batter, being careful not to break berries.
Divide batter evenly between the three 8″ round pans.
Bake for 30-33 minutes, until toothpick inserted into center comes out clean.
Let cool in pans for 10 to 15 minutes, then remove to wire rack to finish cooling.
Make the Cream Cheese Frosting:
Using a stand mixer fitted with the paddle attachment, mix the butter and cream cheese until smooth.
Add vanilla, lemon zest and juice and mix until combined.
Gradually add confectioners sugar, adjusting amount, until desired sweetness is reached. Scrape down the sides of the bowl. Whip until smooth.
Assemble the Cake:
Place one layer of cake onto serving plate or cake stand and top with about one cup of lemon cream cheese frosting. Repeat with second cake layer, more frosting and then last layer of cake. Crumb coat and frost cake with remaining frosting. Decorate with lemon slices, additional blueberries and edible flowers, if desired.
Store in refrigerator. Serve at room temperature.
If using frozen blueberries in the cake, do not thaw before mixing into cake batter. Avoiding over mixing once the berries are added to prevent the cake batter from turning grayish-purple from their juices.
You may bake this as two full-sized 8″ round cake layers. Alternatively, I baked it as three intentionally shorter 8″ round layers – this saves time and effort because the shorter layers do not need to be torted.
If frosting is too thin after whipping, refrigerate for 30 minutes before assembling cake. The chilled frosting will have a thicker consistency. For an even thicker consistency, add additional confectioners’ sugar as desired.