Preheat oven to 350 degrees.
Whip eggs in stand mixer. Add sugar and mix well.
Add orange zest
Combine flour, salt and baking powder and whisk thoroughly to combine.
Add dry mixture to butter mixture and combine well.
Fold in melted butter and gently mix to Incorporate.
Lightly spray madeleine pan with floured cooking spray. Use a pastry brush to ensure pan is well covered.
Spoon about 1 tablespoon into the center of each pan cavity. No need to bang the pan or force the batter into the entire cavity because each well will fill out as the batter bakes.
Bake for about 10-12 minutes or until golden brown around the edges.
The exposed dough will end up a little lighter in color during the baking process. Keep an eye out for the development of browned edges to determine if the batter is fully baked.
Let the Madeleines cool in the hot tray for a few minutes before using a fork to gently lift the cake from the pan.
Allow the Madeleines to cool on a wire rack.
Sprinkle generously with confectioner's sugar before serving.