Prep your 12 shell madeleine pan by buttering it and sifting flour over it. Tap off the excess flour and set aside.
In a medium bowl, combine the flour and the baking powder. In a large bowl, whisk the eggs. Add the sugar and whisk until very well combined. Pour the flour mixture into the eggs and sugar, and combine. Add the lemon extract (and vanilla, if using) and give it a quick stir. Add the melted butter and the honey, and stir until just combined. Cover with plastic wrap and allow to rest in the fridge for 30 minutes.
Preheat the oven to 350 degrees F. Spoon the batter into the 12 shells, and bake on the middle rack until golden and baked through, about 13 minutes. Remove the madeleines from the pan (they should slide right off, but if they don't, slide a knife tip around the edges) and allow to cool on a wire rack. These taste great warm or at room temperature.