Preheat the oven to 350°F (175°C). Grease and flour an 8-inch (20 cm) round cake pan or line it with parchment paper.
In a medium bowl, whisk together the all-purpose flour, baking powder, baking soda, and salt until well combined.
In a large bowl, whisk the granulated sugar and eggs together until the mixture is pale and slightly thickened, about 2-3 minutes.
Add the vegetable oil to the egg mixture and whisk until fully incorporated.
Stir in the whole milk, fresh lemon juice, lemon zest, and vanilla extract until combined.
Gradually add the dry ingredients to the wet ingredients, folding gently with a spatula or whisk until just combined. Do not overmix.
Pour the batter into the prepared cake pan and smooth the top with a spatula.
Bake for 38 to 42 minutes, or until a toothpick inserted into the center comes out clean.
Remove the cake from the oven and allow it to cool in the pan for 10 minutes.
Run a knife around the edges of the cake to loosen it, then invert onto a wire rack to cool completely before serving.