Preheat the oven to 300°F.
Spray three 8 inch loaf pans with baking spray and line them with parchment paper
Zest and juice the lemon. Stir 2 tablespoons of the lemon juice and vanilla extract into the milk. Set aside for later use. The milk will begin to look curdled but it’s supposed to.
In the bowl of a stand mixer using the paddle attachment beat together the butter, salt, and lemon zest. Beat for 5 minutes on medium-high.
Add the sugar gradually beating on medium until light yellow in color. (Around 5 minutes)
Add the eggs one at a time beating well after each addition. Scrape the sides of the bowl as needed.
Sift the flour.
Lower the speed of the mixer and add the flour alternately with the milk, beginning and ending with flour. Stop the mixer and scrape the sides of the bowl occasionally.
After all ingredients have been added, beat on low speed for 1 minute to be sure the flour has been fully incorporated.
Divide evenly between the pans
Place into the oven and bake for 1 hour and 15 minutes OR until a toothpick inserted into the cake comes back clean.
Let cool in the pans 15 minutes before removing