Place the butter in a small bowl then melt it in the microwave or you can use a saucepan to melt the butter. Set aside to cool.
In a medium-sized bowl beat the sugar, eggs and vanilla for five to seven minutes until the mixture becomes pale and has tripled in volume. You can use a handheld mixer or a stand mixer.
In a small bowl combine the flour, baking powder, salt and spices and whisk to combine.
Spoon the flour mixture over the egg batter and gently fold the flour into the batter with a rubber spatula to combine.
Pour the cooled melted butter over the batter and again, gently fold into the batter until combined.
Chill the batter for 1 hour.
Set the oven temperature to 400° F and generously grease and flour the Madeleine pan. Butter is my preferred choice. Some pans are non-stick so you may not have to flour the pan, but I would still grease it.
Spoon a tablespoon of batter into each mold, and you can press down the dough to fill the cavity.
Bake for 8-10 minutes until they are golden brown the bump appears on top. Watch carefully so they don't over-brown.
Let cool for 5 minutes then remove from the pan. See notes.
With a sifter or fine-mesh sieve sprinkle powdered sugar on top of the cakes.
Madeleines are best eaten warm or at room temperature on the same day they are made, but if you have leftovers store them in an airtight container for up to three days.