Preheat the oven to 350° Fahrenheit. Line a 12 hole cupcake tin with paper cupcake liners and set aside.

Add the softened butter and granulated sugar to the bowl of a stand mixer. Beat on a high speed with a flat beater attachment until pale and creamy. Add the eggs, lemon juice and grated lemon zest and beat on a medium-high speed until well combined, scraping the sides of the bowl with a silicone spatula as necessary.

Add the flour, baking powder and salt to the bowl and beat on a low speed until just combined. Add the milk and beat once again on a low speed until just combined. Fold through the blueberries.

Fill the cupcake liners ⅔ full with the cupcake batter. Bake for 15 minutes, or until cooked through. Set aside to cool in the tin for 5 minutes, before transferring to a wire cooling rack to cool completely.

To make the lemon cream cheese frosting, add the softened cream cheese and softened butter to the bowl of a stand mixer. Beat with a wire whisk attachment on a high speed until smooth and creamy. Add the lemon juice and vanilla extract to the cream cheese mixture and beat once again until well combined.

Add the powdered sugar, one cup at a time, and beat on a low speed between each addition, until well combined. Increase the speed to high, and beat for 1 minute or until fluffy.

Transfer the frosting to a piping bag and pipe over the cooled cupcakes. Decorate with additional blueberries and lemon zest, if using.