1. Beat the eggs with the sugar for 3–5 minutes.

2. Gradually add the oil and beat briefly.

3. Mix the flour with the baking powder and sift. With the mixer on low speed, add a few spoonfuls of flour and a little water to the eggs. Repeat, alternating the two, until all the flour and water have been added.

4. Add the grated lemon zest and vanilla.

5. Pour the batter into a tin greased with butter and dusted with flour.

6. Bake at 170 °C in the lower part of a preheated oven for 40 minutes. Dust with icing sugar after removing the cake from the oven.