For the Lemon Cupcakes:

1. Preheat the oven to 350°F (175°C) and line a cupcake pan with cupcake liners.
2. In a large bowl, whisk together cake flour, baking powder, and salt; set aside.
3. Using a stand mixer or handheld mixer, beat the butter and sugar together for about 2 minutes, until light and fluffy.
4. Add the eggs one at a time, mixing well after each addition.
5. Gradually mix in half of the dry ingredients, followed by half of the milk, then add the vanilla extract, lemon zest, and lemon juice. Mix until smooth.
6. Add the remaining dry ingredients and milk, mixing until no lumps remain.
7. Fill the cupcake liners about two-thirds full.
8. Bake for 18–22 minutes, or until a toothpick inserted in the center comes out clean.
9. Remove from the oven and cool in the pan for 5 minutes, then transfer to a wire rack to cool completely.

For the Cream Cheese Frosting:

1. In a large mixing bowl, beat together butter and cream cheese until smooth and creamy.
2. Gradually add powdered sugar, one cup at a time, mixing well after each addition.
3. Mix in the vanilla extract and beat until the frosting is fluffy and spreadable.

Frost the cooled cupcakes using a piping bag or knife. Garnish with lemon slices or zest if desired.