Heat oven to 350 F. Butter and flour a 9 inch round cake pan.
In a food processor or blender, blend the milk and mint until the mint is totally combined. It will look light green at first, and will darken as you make the cake batter.
In the bowl of a stand mixer or bowl fitted with a hand mixer, beat together the eggs, zest and sugar until several shades lighter, airy and fluffy, 5-7 minutes.
While mixer is running, drizzle in the oil slowly, allowing it to emulsify and thoroughly combine.
Sift in the cake flour and add the baking soda and baking powder.
Add mint milk and lemon juice, and beat to just combine.
Pour into prepared pan, sprinkle with granulated sugar to top.
Bake until a cake tester comes out clean, and check for doneness 40 minutes. This cake will rise above the cake rim while baking then fall as it fully bakes and cools.