Preheat oven to 350 degrees.
Spray four 8 inch pans with baking spray. Set aside.
In a medium bowl, whisk together flour, baking powder, baking soda, salt, and lemon zest. Set aside.
In the bowl of an electric mixer, beat sugar and butter until fluffy, about 3-4 minutes.
Beat in egg yolks.
Add eggs, one at a time, beating well after each addition.
Beat in sour cream and lemon juice.
Stir in half of flour mixture.
Add all of milk.
Stir in remainder of flour mixture.
Add vanilla.
Divide evenly among prepared pans, about 13 ounces per pan.
Bake for 15 minutes, or until cake tests done.