Preheat oven to 350°F (175°C). Line a 12-cup muffin tin with paper liners.

In a large bowl, whisk together flour, sugar, baking powder, and salt.

In a separate bowl, cream together softened butter until light and fluffy. Beat in eggs one at a time. Stir in milk, lemon zest, and lemon juice.

Gradually add the dry ingredients to the wet ingredients, mixing until just combined. Do not overmix.

Divide the batter evenly among the prepared muffin cups, filling each about two-thirds full.

Bake for 20-22 minutes, or until a toothpick inserted into the center comes out clean.

Let the cupcakes cool in the muffin tin for a few minutes before transferring them to a wire rack to cool completely.

In a medium bowl, beat together softened cream cheese and butter until smooth and creamy.

Gradually add powdered sugar, beating until well combined and fluffy.

Stir in lemon juice and lemon extract (if using) until smooth.

Once cupcakes are completely cool, frost them generously with the lemon cream cheese frosting.