Preheat your oven to 175°C (350°F). Grease and flour a 9-inch round or loaf cake pan.
In a large mixing bowl, whisk together the eggs and sugar until light and fluffy.
Stir in the lemon juice and lemon zest until fully combined.
Add the vegetable oil and milk, whisking until smooth.
Sift in the flour and baking powder, then fold into the wet ingredients until no lumps remain.
Pour the batter into the prepared cake pan and smooth the top.
Bake for 40–45 minutes, or until a toothpick inserted into the center comes out clean.
Let the cake cool in the pan for 10 minutes before transferring to a wire rack to cool completely.
Serve plain, dusted with powdered sugar, or topped with a simple lemon glaze if desired.