Preheat the oven to 180ºC.
Mix eggs and sugar in a bowl and whisk with an electric mixer until creamy - around 5 minutes. The mixture should be pale yellow.
Add the olive oil, milk, vanilla extract, and lemon zest. Mix well.
In a different bowl, sift the flour, baking powder, baking soda, and salt.
Add the wet mixture to the flour mixture and mix with a wooden spoon until fully combined.
Line a cupcake mold (6-8) with cupcake liners and pour over the mixture, leaving around 1 cm on top.
Cover each with sugar.
Bake for 12-15 minutes, or until you pinch them with a toothpick and it comes out dry. Serve warm.