Heat the Oven: Begin by setting your oven to 375°F (190°C) so it's properly heated when you're ready to bake. Prepare your Madeleine pan by greasing it with butter or cooking spray, then lightly dusting it with flour to ensure the cookies release easily.

Melt the Butter: In a small saucepan over medium heat, melt the unsalted butter until fully liquefied. Remove from heat, then stir in the heavy cream until well combined. Allow the mixture to cool slightly while you gather and prepare the remaining ingredients.

Mix Dry Ingredients: In a medium bowl, sift together the all-purpose flour, baking powder, and a pinch of salt. This will ensure a smooth, lump-free batter.

Whisk the Wet Ingredients: In a separate large bowl, whisk the eggs and granulated sugar until the mixture becomes light and fluffy. This step is crucial for creating that airy, delicate texture in your Madeleines. Add the vanilla extract (and lemon zest, if you’re using it) and whisk to combine.

Combine Wet and Dry Ingredients: Slowly incorporate the sifted dry ingredients into the wet mixture, stirring gently until just combined. Avoid overmixing to maintain a light texture. The batter should be thick, smooth, and free of lumps.

Fold in the Butter-Cream Mixture: Gently fold the melted butter and cream mixture into the batter. This will give your Madeleines their moist, buttery richness. Stir until everything is evenly incorporated.

Spoon the Batter: Spoon the batter into the prepared Madeleine pan, filling each cavity about two-thirds full. Be careful not to overfill; this allows the cookies to rise nicely and form the iconic shell shape.

Bake: Bake the Madeleines in the preheated oven for 10-12 minutes, or until they turn golden brown around the edges. You can check if they’re done by gently pressing on the tops—if they spring back, they’re ready!

Cool and Serve: Once baked, remove the Madeleines from the pan and let them cool slightly on a wire rack. If you’d like, dust them with a little powdered sugar before serving for that classic, elegant touch.