01 - Preheat oven to 350°F. Grease and flour two 8-inch round cake pans, lining the bottoms with parchment paper.
02 - Whisk together flour, baking powder, baking soda, and salt in a medium bowl.
03 - Beat butter and sugar in a large bowl until light and fluffy, approximately 3 minutes.
04 - Add eggs one at a time, mixing well after each addition. Stir in lemon zest, lemon juice, and vanilla extract.
05 - Add the dry mixture in three parts, alternating with milk, starting and finishing with dry ingredients. Mix just until combined.
06 - Toss blueberries with 1 tablespoon flour, then gently fold them into the batter.
07 - Distribute batter evenly between the prepared pans.
08 - Bake for 30 to 35 minutes or until a toothpick comes out clean when inserted in the center.
09 - Allow cakes to cool in pans for 10 minutes, then remove and transfer to a wire rack to cool completely.
10 - Beat cream cheese and butter until smooth. Gradually add powdered sugar, lemon zest, lemon juice, vanilla, and salt. Beat until fluffy.
11 - Place one cake layer on a serving plate, spread frosting over the top. Add second layer and cover sides and top with remaining frosting.
12 - Decorate with fresh blueberries and extra lemon zest if desired.