Preheat oven to 350 degrees F (176 degrees C).
Into the bowl of a stand mixer, add Butter (2 stick) and Granulated Sugar (2 cup). Mix until smooth.
In a mixing bowl, sift together All-Purpose Flour (3 cup), Baking Powder (1/2 teaspoon), Baking Soda (1/2 teaspoon), in Salt (1 teaspoon). In another bowl, combine 1/4 cup of juice from the Lemon (5) and Milk (3/4 cup).
Into the stand mixer, add Egg (4) one at a time. Mix until smooth.
Add Vanilla Extract (1 teaspoon) and 1/3 cup of lemon zest. Mix until well combined.
Add 1/3 of the dry ingredients, followed by 1/2 of the milk and lemon juice mixture. Repeat until all ingredients are incorporated.
Transfer the batter into two 7 by 11-inch greased baking tins.
Bake for 40-45 minutes.
Allow cakes to cool.
Frost cake as desired, making sure they're completely cooled before frosting or it will melt.