Preheat the oven to 180°C (356°F).
Finely grate the lemon peel to prepare lemon zest.
In a bowl, mix eggs and sugar together.
Sift cake flour and baking powder into the bowl and mix.
Add melted butter, lemon juice, and lemon zest, and mix well.
Pour the batter into a madeleine mold.
Bake in the oven for 10 to 12 minutes.
Cool and serve.