Whisk together the flour, baking powder, and salt 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 beat on high with an electric mixer until the egg/sugar mixture thickens, about 5 minutes. Beat in the honey and vanilla extract.
Using a flexible spatula, 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.
Press a piece of plastic wrap against the surface of the batter and chill for at least 1 hour. (See Note 1)
An hour or so before baking, spray the molds of a 16-shell madeleine pan with baker's non-stick spray. Using a 1 ½-inch cookie scoop, divide the batter evenly among the molds and refrigerate for 1 hour more. (See Notes 2 and 3)
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°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. Transfer to a cooling rack and allow the madeleines to cool to room temperature. If not glazing, dust with confectioners' sugar if desired.