Ingredients:
Unsalted butter, melted and cooled – ½ cup (113 g)
Granulated sugar – ½ cup (100 g)
Large eggs – 2 (about 100 g without shells)
Vanilla extract – 1 teaspoon (5 g)
Lemon zest (optional but classic) – from 1 lemon (about 2 g)
All-purpose flour – 1 cup (125 g)
Baking powder – 1 teaspoon (4 g)
Fine salt – ¼ teaspoon (1.5 g)
Instructions
Butter and lightly flour a madeleine pan, tapping out excess, then chill the pan in the fridge. Whisk the eggs and sugar together until pale and slightly thickened, then whisk in the vanilla and lemon zest. In a separate bowl, combine the flour, baking powder, and salt, and gently fold this into the egg mixture just until smooth. Slowly fold in the melted butter until fully incorporated and glossy. Cover the batter and rest it in the fridge for at least 30 minutes for the classic hump.
Preheat the oven to 190°C (375°F). Spoon the batter into the chilled pan, filling each shell about three-quarters full without spreading. Bake until the edges are golden and the centers spring back lightly, about 9–11 minutes. Turn the cakes out immediately onto a rack. Serve warm or cooled, plain or dusted lightly with powdered sugar.