Preheat oven to 350 degrees F. Butter a 9"x13" baking pan and line with parchment paper. Set aside.
Whisk together flour, baking powder, baking soda, and salt. Set aside.
Using a stand mixer or hand held mixer, whip together egg yolks and sugar on medium speed until mixture has thickened and is pale in color. Add milk and mix until incorporated. Add dry flour mixture and mix until combined.
In a clean bowl, using a hand held mixer, whip whip egg whites to medium peaks. In three additions, gently fold whipped egg whites into batter. Fold until there are no longer any white streaks of egg whites. Be careful not to overmix.
Transfer cake batter to prepared baking pan. Spread into an even layer. Bake for 35 minutes until top of cake is golden brown and a toothpick inserted in center of cake comes out clean. Leave cake in pan and let cool to room temperature.