Preheat your oven to 350°F (175°C) and line a muffin tin with cupcake liners.
In a medium bowl, whisk together the flour, baking powder, baking soda, and salt.
In a large bowl, cream together the softened butter and granulated sugar until light and fluffy, about 3-4 minutes.
Add the eggs, one at a time, mixing well after each addition. Then stir in the vanilla extract, lemon zest, and fresh lemon juice.
Gradually add the dry ingredients to the wet mixture, alternating with any remaining lemon juice, and mix until just combined.
Scoop the batter into the prepared cupcake liners, filling them about two-thirds full.
Bake for 18-20 minutes or until a toothpick inserted in the center comes out clean.
Remove from the oven and allow the cupcakes to cool in the pan for 5 minutes before transferring to a wire rack to cool completely.
In a small bowl, combine the powdered sugar and lemon juice to make the frosting until smooth and spreadable.
Frost the cooled cupcakes generously, and garnish with additional lemon zest if desired.
