Lemon zest (you can substitute this with lemon oil)
half a lemon's worth
Combine the flour and the baking powder, then sift. Zest the lemon and melt the butter in a microwave.
Crack eggs into a bowl, add the sugar and beat well.
Add the flour and the lemon zest and mix until well combined.
Add the melted butter in 2-3 doses, and mix until it is well incorporated and the batter is glossy.
Cover with plastic wrap and let it rest in the refrigerator for 1 hour~6 hours. You can leave the whisk in the bowl.
Prepare the mold while you let the batter rest. Use a ball of plastic wrap and use it to spread shortening on the mold (no need for any flour!).
Or, use a ball of plastic wrap to spread some butter (just the amount left in the bowl that you used to melt it would be enough) on the mold, chill in the refrigerator, then sift some cake flour on it (dust off the excess flour).
Mix the batter until it is smooth, then fill the mold by about 80% (I used two spoons). Pop large bubbles with skewers, etc.
Bake at 180℃ for 20 minutes, then remove immediately from the mold and cool. Once they have cooled to room temperature, put them in a bag to keep them from drying out.
Story Behind this Recipe
I have been thinking that, since I'm going to let the batter rest anyways, I don't really need to fold the batter. So I tried to make it by just mixing everything together and it was still tasty, and thus I settled on this easy method.
The cake will not brown evenly if you use a silicone mold, so I personally discourage its use. By using a traditional mold, you will get beautifully baked madeleines.