Preheat oven to 375F. Grease and lightly flour Madeleine pans.
2
Sift flour and baking powder together and set aside.
3
Cream together butter, sugar and lemon zest until smooth. In a separate bowl, chime eggs, milk and vanilla extract. Add egg mixture to butter mixture in three additions, beating well after each addition. On low speed, mix in dry ingredients until just moistened. Scrape down bowl as needed.
4
Pipe into prepares Madeleine pans. Bake until edges are golden brown, about 12-14 minutes depending on the size of your pan. Turn onto wire rack while still warm. Cool before serving.