01 - Preheat oven to 350°F. Grease and flour two 8-inch round cake pans and line bottoms with parchment paper.
02 - In a medium bowl, whisk together flour, baking powder, baking soda, and salt; set aside.
03 - In a large bowl, beat butter and sugar until light and fluffy, about 3 minutes.
04 - Beat in eggs one at a time, then incorporate lemon zest, lemon juice, and vanilla extract.
05 - Add flour mixture in three parts, alternating with milk, starting and ending with flour; mix until just combined.
06 - Gently fold the blueberries that have been tossed in flour into the batter.
07 - Divide batter evenly between prepared pans and smooth the tops.
08 - Bake for 30 to 35 minutes or until a toothpick inserted into the center comes out clean.
09 - Allow cakes to cool in pans for 10 minutes before transferring to wire racks to cool completely.
10 - Beat cream cheese and butter until smooth; gradually add powdered sugar, then mix in lemon juice, vanilla, and a pinch of salt until fluffy.
11 - Spread a layer of frosting over one cake layer, place the second layer on top, then cover top and sides with frosting. Optionally decorate with additional blueberries and lemon zest.