Preheat the 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. Set aside.

In a large bowl, cream together the butter and sugar until light and fluffy. Add the eggs, one at a time, beating well after each addition. Stir in the vanilla extract.

Mix in the sour cream, lemon juice, and lemon zest until well combined.

Gradually add the dry ingredients to the wet ingredients, mixing until just combined.

Divide the batter evenly among the cupcake liners, filling each about 2/3 full.

Bake for 18-20 minutes, or until a toothpick inserted into the center comes out clean. Allow the cupcakes to cool completely before frosting.

For the cream cheese frosting, beat together the cream cheese and butter until smooth. Gradually add the powdered sugar, beating until light and fluffy. Mix in the vanilla extract and lemon juice.

Frost the cooled cupcakes with the cream cheese frosting and garnish with lemon zest.