• Preheat oven to 350F and line a 12 cup cupcake pan with cupcake liners.
• In the bowl of a stand mixer, cream together the butter and sugar until light and fluffy.
• Add the eggs, vanilla extract, milk and lemon juice and mix thoroughly. Note: If you do not have a stand mixer, you can do this using a large mixing bowl and an electric mixer/ hand mixer.
• Mix the baking powder, flour, lemon zest, and salt in a large mixing bowl and then slowly mix it into the wet ingredients to form a smooth batter. Remove the bowl from the stand mixer.
• Toss the blueberries in a tablespoon of flour and then fold the blueberries into the batter with a spatula.
• Spoon the cupcake batter into the cupcake liners, filling each until they are 3/4 full. Bake in the oven for 15 minutes or until a toothpick inserted into the center comes out clean. Let cool in pan for 3 minutes, then transfer to a cooling rack to cool completely.

For the Frosting

• In the bowl of a stand mixer fitted with the paddle attachment, add the cream cheese and beat until smooth. Add the butter and beat to combine. Next, add the lemon juice and powdered sugar and mix until everything is combined and smooth.
• Transfer to a piping bag and pipe onto cooled cupcakes. Top the cupcakes with fresh blueberries and lemon zest if desired.