There's a chocolate one below that sounds good but I haven't tried it. I always make the traditional one from Craig Claiborne.

Here is a link that might be useful: Chocolate Madeleine

These were good!

Meyer Lemon Madeleines
(recipe from newspaper they adapted from a Julia Child recipe)

2 large eggs, lightly beaten in a 2-cup measure
2/3 cup sugar
1 cup all-purpose flour, plus 1 tablespoon extra for preparing molds
5 ounces (1 1/4 sticks) unsalted butter, cut into 6 pieces
Pinch of salt
Grated rind of 2 Meyer lemons
1 tablespoon of freshly squeezed Meyer lemon
Confectioners' sugar for sprinkling

Measure 1/4 cup of eggs into a bowl, then, using a wooden spoon, beat in the sugar and cup of flour. When thoroughly blended, let rest 10 minutes. Meanwhile, melt the butter in a 6-cup saucepan, bring it to a boil, and let it brown lightly.

Place 1 tablespoon flour in a small bowl and blend in 1 1/2 tablespoons browned butter. Set aside for preparing madeleine pans. Stir the rest of the butter over a bowl of ice cubes until cool but liquid. Blend it and the last of the eggs into the batter along with the salt, lemon rind, and juice.

Preheat oven to 375 degrees and set the racks in the upper and lower middle levels.

Paint the madeleine cups with the reserved butter-flour mixture. Divide the batter into 24 lumps of a generous tablespoon each and drop them into the madeleine cups.

Bake in preheated oven 15 minutes until the cakes are lightly browned around the edges, humped in the middle, and slightly shrunken from the cups. Unmold onto a rack. When cool, turn shell side up and dust with confectioners' sugar. Keep in an airtight container or freeze.