Begin by preheating your oven to 350°F (177°C). Grease a 9-inch (23cm) springform or cake pan and line the bottom with parchment paper to ensure easy removal after baking.
In a large bowl, whisk together the flour, baking powder, baking soda, and salt until well combined. This ensures even distribution of the leavening agents throughout the cake.
In the bowl of your stand mixer fitted with the whisk attachment, combine the granulated sugar and lemon zest. Use your fingertips to rub the zest into the sugar until it resembles wet sand. This crucial step releases the essential oils from the zest, infusing the sugar with intense lemon flavor.
On low speed, whisk the eggs into the lemon sugar one at a time until combined. Then increase the speed to high and whip for 4-5 minutes. The mixture will become thick, pale yellow, and form ribbons when the whisk is lifted. This aeration is key to a light texture.
With the mixer on medium speed, slowly stream in the olive oil in a steady flow. Once all the oil is incorporated, increase the speed to high for 1 minute to emulsify completely. Scrape down the sides and bottom of the bowl to ensure everything is well mixed.
On low speed, add the lemon juice and milk, then gradually add the dry ingredients. Mix just until incorporated - overmixing will develop too much gluten and make the cake tough.