In a large bowl, beat the eggs, egg yolk, and sugar on medium-high speed
In a small bowl, combine the flour, baking powder, and salt. Stir to break up any clumps
Gently stir in the lemon zest and lemon juice
Fold in the flour mixture in four additions, incorporating it gently and breaking up any pockets of flour without deflating the air too much
Stir in the melted butter until fully incorporated.
Cover the batter and allow it to rest in the fridge for at least 30 minutes
Scoop a heaping tablespoon (15 ml) of batter into each well of the pan.
Bake for 9–12 minutes until golden brown at the edges and they bounce back in the center when lightly touched
Allow the madeleines to cool for 3-5 minutes in the pan
These madeleines are at their best when eaten the same day.