Preheat oven to 350 degrees.
Spray 2 loaf pans (4 mini loaves) with cooking spray, set aside.
Combine milk, eggs, lemon juice, and vanilla and whisk until combined, set aside.
In the bowl of a mixer - combine flour, sugar, baking powder, salt, and freshly grated lemon zest and mix to combine.
Add the softened butter to the flour mixture. Cream for 2-3 minutes until fluffy.
Gradually add the milk mixture.
Divide the batter into the prepared loaf pans.
Bake in oven for ~30-35 minutes (less cooking time for mini loaves).
When the tops are about to crack, score the tops in one line with a sharp, oiled knife to create an even crack. Then, place an oiled piece of foil on top of the cakes, oil side down.
Continue to bake for 25-30 minutes.
Total baking time is 55-65 minutes depending on your oven and the size of your loaves.
When a toothpick removed from the center of the cake comes out clean, the cakes are done. Remove from oven and let cool for 10 minutes on a rack before turning the cakes out.
Let cool completely.