Makes one 9-inch cake
|Butter (for the pan)|
|Flour (for the pan)|
|1||teaspoon baking powder|
|2||tablespoons unsalted butter, cut into 2 pieces|
|1 1/2||teaspoons vanilla extract|
|3||large egg yolks|
1. Set the oven at 350 degrees and position a rack in the center. Butter and flour a 9-inch round cake pan.
2. In a large bowl, combine the flour and baking powder; set aside.
3. In a small saucepan over low heat, combine the milk and butter. Heat until the butter melts. Remove from the heat and add the vanilla. Set aside.
4. In an electric mixer, beat the eggs, egg yolks, and sugar at high speed for 3 minutes or until the mixture triples in volume and turns pale yellow. Reduce the speed to medium and continue beating for 3 minutes. The mixture will continue to increase in volume and thicken.
5. With the mixer on the lowest speed, sprinkle 1/4 of the flour mixture into the bowl and beat until no trace of white remains. Repeat with the remaining flour mixture in 2 additions. Reserve the empty flour bowl.
6. Pour half of batter into the empty flour bowl. Pour the warm milk mixture into this batter and stir gently to combine. Slowly pour the milk batter into the other mixing bowl with the remaining batter.
7. Using a rubber spatula, fold the mixtures together quickly but gently until blended. Work quickly to prevent too much air from escaping.
8. Pour the batter into the prepared pan. Bake in the center of the oven for 30 to 40 minutes or until the edges pull back from the pan and a toothpick inserted in the center of the cake comes out clean. Set the cake on a rack to cool.
9. Run a knife around the edge of the pan and turn the cake out onto a plate, then use another plate to flip the cake so it is right side up.