In a small saucepan over medium heat, melt butter and continue simmering until browned to a caramel color. Set aside and allow to cool.
Sift flour, baking powder and salt into a bowl, combine and set aside.
Add eggs and sugar to the bowl of a stand mixer fitted with a whisk attachment OR to a large bowl if using an electric hand mixer. Beat on high until mixture is a light yellow color with a thick silky texture, about 8 minutes. You’ll see the beater leave trails when it’s ready. Mix in vanilla and lemon zest toward end.
Once mixing is done, use a rubber spatula to gently fold in dry ingredients into egg mixture and combine. Make sure all flour is combined, but avoid stirring too rapidly or too long.
Drizzle in browned butter now at room temperature and gently combine.
Cover batter with cellophane, place touching batter versus top of bowl to avoid surface skin. Chill batter as well as buttered baking tin for 1 hour. Chilling baking tin is one more way to help give the cakes their popular bump.
After 1 hour, preheat oven to 190C/375F. Important to preheat oven before bringing out batter from fridge.
Add a small ice cream scoop of batter (or 1 Tablespoon) into each scallop-shaped well. Don’t press or spread batter as you want to avoid losing the air bubbles.
Bake for 9-12 minutes (keep an eye on it), times vary depending on oven and thickness of pan.
Once fully cooled at room temperature, you may top with pink granulated sugar, sold ready-made or you may make your own with drop of pink food coloring.