From Dorie Greenspan's Baking Chez Moi
For the madeleines:
2/3 c all-purpose flour
1 t baking powder
1/4 t fleur de sel or a pinch of fine sea salt
1/3 c sugar
finely grated zest of 1 lemon
2 large eggs, at room temp
1 TB honey
1 t pure vanilla extract
1 stick unsalted butter, melted and still warm
2 TB whole milk
confectioners' sugar for dusting (optional)
For the glaze:
1 c confectioners' sugar, sifted
about 1/4 c freshly squeezed lemon juice
Whisk together the flour, baking powder, and salt together in a small bowl; set aside.
Working in a large bowl, rub the sugar and lemon zest together with your fingertips until the sugar is moist and fragrant. Add the eggs and whisk energetically. You want the egg-sugar mixture to thicken ever so slightly and pale just a little; this could take a couple of minutes (if you'd like, you can use a mixer). When the whisk leaves tracks, beat in the honey and vanilla. Using a gentler touch - and a flexible spatula, if you'd like - fold in the dry ingredients, folding only until they disappear into the batter. Finally fold in the warm melted butter and, when it's incorporated, the milk. You'll have a smooth, shiny batter. Press a piece of plastic film against the surface of the batter and chill for at least 1 hour. (The batter can be kept in the refrigerator for up to 2 days.)
An hour or so before you're ready to bake, butter the molds of a 12-shell madeleine pan, dust with flour and tap out the excess. Even if you have non-stick or silicone molds, it's a good idea to give them the butter-flour treatment. (Alternatively, you can use baker's spray.)
Spoon the batter into the molds - don't worry about spreading it evenly; the oven's heat will take care of that - and refrigerate for 1 hour more. (You can cover the batter lightly with a sheet of wax or parchment paper, but inevitably some of the batter will stick, so I leave the pan bare.)
When you're ready to bake: center a rack in the oven, put a large heavy baking sheet on the rack and preheat the oven to 400 degrees F.
Place the madeleine pan on the hot baking sheet and bake for 11 to 13 minutes, or until the cakes are golden and the big bumps on their tops spring back when touched. Remove the pan from the oven and immediately release the madeleines from the molds by rapping the edge of the pan against the counter. Gently pry any recalcitrant madeleines from the pan using your fingers or a table knife. Transfer to a cooling rack and allow them to cool to room temp. (If you're not glazing them, you can serve them warm. Unglazed madeleines are nice with a dusting of confectioners' sugar.)
To glaze the madeleines: center a rack in the one and preheat the oven to 500 degrees F. Line a baking sheet with parchment or foil and put a cooling rack on it.
Put the confectioners' sugar in a bowl that's large enough to allow you to dip the madeleines into the glaze. Whisk in the lemon juice a little at a time until you get a glaze that's about as thick as heavy cream. (You'll have more glaze than you need, but it's hard to work with a smaller amount.)
One by one, dip (don't soak) the bump side of the madeleines in the glaze and put them bump side up on the cooling rack. Slide them into the oven, close the door and stay put: it takes 1 to 3 minutes for the glaze to melt and coat the madeleines, and you want to be there to pull them out of the oven at the first sign of a bubble in the glaze. Remove from the oven, lift the hot cooling rack with the cakes onto another cooling rack, to protect your countertop, and let cool to room temp.