Judit bought me the pan, she gets the credit.
1/2 cup unsalted butter
1 cup all-purpose flour
1/2 teaspoon baking powder
1/4 teaspoon salt
3 large eggs at room temperature
1/2 cup sugar
2 tablespoons firmly packed light brown sugar
1 teaspoon pure vanilla extract
1 teaspoon freshly grated lemon or orange zest
Melt butter and allow it to cool slightly
Whisk flour, baking powder and salt in a small bowl until blended
Beat eggs and sugar at medium-high speed until the mixture has tripled in volume and is thick (about 5 minutes) then add vanilla.
Sift a small amount of flour over the egg mixture then using a large spatula, fold in the flour. Sift the rest of the flour over the egg mixture and fold in. Make sure all the flour is incorporated but do not overtax the batter or it will deflate.
Whisk a small amount of egg mixture into the melted butter to lighten it. Then fold it into the egg/flour mixture in three additions. Cove and refrigerate for at least 30 minutes or several house until slightly firm.
Preheat oven to 375 degrees. Generously butter and flour a madeline pan then refrigerate it for a few minutes.
Using a small ice cream scoop, drop a generous tablespoon of the batter into the center of each prepared mold leaving the batter mounded in the center to get the classic “humped” appearance.
Bake for 11 to 13 minutes until the edges are golden brown and the centers spring back when lightly touched. Do not over bake.
After they cool for about two minutes, rap the pan sharply against the control to release them and let them cool smooth side down. Serve with powdered sugar, warm.
I got the recipe here