Prepare all ingredients and wash the lemon thoroughly.

Grate the yellow part of the lemon peel to create zest.

Beat the eggs in a mixing bowl.

Add sugar to the eggs and mix well.

Add the lemon zest and mix thoroughly.

Squeeze the juice of half a lemon and add it to the mixture.

Sift the flour and baking powder into the mixture and mix until smooth.

Melt the butter in the microwave for 20 seconds and add it to the batter.

Add vanilla extract and mix until the batter is smooth.

Transfer the batter into a piping bag or use a spoon to portion it.

Grease the madeleine molds lightly with oil or butter.

Fill the molds up to 80% with the batter.