01 - Preheat oven to 350°F. Grease and flour a 9-inch round cake pan or line it with parchment paper.
02 - In a medium bowl, whisk together flour, baking powder, baking soda, and salt until combined.
03 - In a large bowl, beat unsalted butter and granulated sugar until light and fluffy, about 2 to 3 minutes.
04 - Add eggs one at a time to the butter mixture, mixing thoroughly after each addition. Stir in vanilla extract and lemon zest.
05 - Alternate mixing in half of the dry ingredient mixture, then lemon juice and milk, followed by the remaining dry ingredients. Stir just until combined.
06 - Toss blueberries with 1 tablespoon flour, then gently fold into the batter.
07 - Pour batter into the prepared pan and smooth the surface. Bake for 30 to 35 minutes or until a toothpick inserted in the center comes out clean.
08 - Allow cake to cool in the pan for 10 minutes, then transfer to a wire rack to cool completely.
09 - Beat cream cheese and unsalted butter together until smooth. Gradually add powdered sugar, lemon juice, lemon zest, vanilla extract, and salt. Beat until light and fluffy.
10 - Spread frosting evenly over the cooled cake. Optionally, garnish with extra blueberries and lemon zest.