Preheat oven to 325ºF. Add a circle of parchment paper to the base of a 9-inch springform pan and spray the parchment paper and the sides of the pan very well with cooking spray; set aside. It is important to make sure to only use a springform pan for this cake to allow for rising.
Add the milk, lemon zest, lemon juice, and Limoncello, then whisk until incorporated; don't overmix. The batter is on the thin side; this is normal. Pour batter into prepared pan. Place pan on a baking sheet as insurance against a leaky springform pan and bake for about 65-75 minutes. Start checking after 60 minutes since all ovens vary. Cake will be golden browned and domed in the center when done, and a toothpick inserted in the center will come out clean or with a few moist crumbs.
Allow the cake to cool in the springform pan for about an hour before releasing it and allow the cake to finish cooling on a wire rack.
