1. Preheat the oven to 350º and position a rack in the center. Grease and flour two 9" round cake pans
2. Using the whisk attachment on your mixer (or if you’re using a hand mixer, the regular beaters), whip the egg yolks, eggs and sugar on high speed for 3 minutes. The mixture will triple in volume and turn a very pale yellow. Reduce the speed to medium and continue mixing 3 minutes (if using a hand mixer, keep the speed at high and continue mixing). The mixture will continue to increase in volume and thicken
3. Combine the flour and baking powder in a large bowl and set aside
4. Heat the milk and butter in a small saucepan over low heat. As soon as the butter is melted, remove from heat and add the vanilla
5. With the mixer on the lowest setting, slowly sprinkle ¼ of the flour mixture over the eggs and mix until no trace of white remains. Repeat with the remaining flour mixture, reserving the empty flour bowl. When the flour is fully incorporated, the mixture will be thick and stiff; if you let the batter pour off the whisk it will fall back on itself like a ribbon
6. Pour ½ of the batter into the empty flour bowl. Pour the milk mixture into the batter and stir to combine. Slowly pour the milk/batter mixture back into the mixing bowl. Fold the mixtures together quickly but gently, until they are fully incorporated. You will see tiny air bubbles appear on the surface; work quickly to prevent too much air from escaping
7. Divide the batter between the prepared pans and place on the center oven rack. Bake for 20-30 minutes, or until the edges pull back from the pan and a toothpick inserted in the center of the cake comes out clean. Cool on a rack
8. When the cake is cool, run a knife along the perimeter of the pan and turn out onto a plate, and then use another plate to flip the cake again so it is right side up
9. Slice, fill, frost, sprinkle with confectioners’ sugar, dress it up with glaze, whipped cream, fresh berries, or sauces

Adapted from One Cake, One Hundred Desserts by Greg Case