Brown the ½ cup of butter on the stovetop, then pour into a heat proof bowl and allow to cool slightly while you mix the batter
In a medium bowl, whisk together 1 cup of all purpose flour, ¼ tsp of baking powder and ¼ tsp of salt. Set aside
In the bowl of a stand mixer fitted with the whisk attachment, or in a large bowl using a hand mixer, beat together the 2 large room temperature eggs and ½ cup of granulated sugar for a minimum of 10 minutes. The mixture will turn light yellow and fluffy and leave a trail known as the ribbon stage.
Add 1 tsp of vanilla, 1 tsp of lemon zest and 2 Tbsp of orange zest to the mixture and beat until combined.
Gently pour fluffy egg mixture into the dry ingredients and fold delicately until the batter is combined. Make sure to mix well so as to not have any pockets of flour at the bottom, however do not overmix the batter.
Pour in the cooled brown butter and mix until combined.
Cover the batter with plastic wrap with the plastic wrap touching the top of the batter and chill in the refrigerator for at least 1 hour or overnight. This step is crucial to the bake and cannot be skipped!
Preheat the oven to 350℉ (180℃) and spray the madeleine pan with nonstick spray generously.
Use a small spoon or a 1” scoop to place even amounts of batter into each madeleine shell. Bake for 8-10 minutes. Remove from the oven and allow to cool completely.
Once cooled, remove from the tin, clean the silicone tin to use for the chocolate decor.