Step 1

Melt the butter. Melt the butter in a small saucepan. If you feel you can get it slightly toasty brown, go right ahead and do so by leaving it to bubble in the pan until it smells toasty and starts to color. Just remember that the butter will turn very quickly from toasty to burnt and that it will continue to color after it is off the heat unless you pour it into a new container. Spoon 3 tablespoons of the butter into a small bowl or cup and set aside. Let the rest of the butter cool slightly.

Step 2

Prepare the dry ingredients and the wet ingredients in separate bowls.In a medium bowl, whisk together 1 cup of the flour and the sugar, and set aside. In another medium bowl, whisk the 2 eggs with the vanilla, salt, lemon juice, and lemon zest until the eggs are frothy.

Step 3

Combine the dry and wet ingredients. Add the eggs to the flour. Using a spatula, stir until just combined. Add the remaining 1 stick melted butter and continue to stir. It may take a minute for the butter to blend into the mixture but do not over mix.

Step 4

Rest the batter. Cover the bowl with a plate (or plastic wrap) and place in the refrigerator to rest at least 1 hour and up to overnight.

Step 5

Prepare the pans. Add the remaining 1 tablespoon flour to the 3 tablespoons reserved butter and stir to combine. Using a pastry brush, brush the interiors of the shells with the butter-flour mixture so that they are well coated. Place the pans in the freezer for at least an hour.

Step 6

Preheat the oven and fill pans. Preheat the oven to 350°F. Remove the batter from the refrigerator and one pan from the freezer. Fill each well in the madeleine pan with 1 tablespoon of the batter. Remove the other pan and fill in the same way.

Step 7

Bake the madeleines. Place both pans on a baking sheet for easy handling and place in the oven. Check after 8 minutes and rotate plans. Check again 5 minutes later. The madeleines should be browning around the edges and puffed up a little in the middle. Using your forefinger, press lightly on the center hump -- when the madeleines are finished baking, it should spring back at your touch.

Step 8

Cool and dust with sugar. Remove the madeleines from the oven and let cool for 2 minutes. Using a fork, gently loosen the madeleines from their molds and then tip the whole pan out onto a cooling wrack or tea towel. Once cool, dust lightly with powdered sugar and serve. If you are freezing or storing the madeleines, do not dust with the sugar until you are about to serve.

Step 9

To store. Store cooled madeleines in an airtight container for a few days or freeze them in a double wrapping of plastic wrap for several months. Let the cakes defrost before dusting with sugar.