Preheat oven to 350°F (175°C). Grease and flour a 9x13 inch baking pan.
In a large bowl, whisk together flour, baking powder, and salt. Set aside.
In another bowl, beat egg yolks with 3/4 cup sugar until pale yellow. Stir in milk and vanilla. Pour egg yolk mixture over the flour mixture and stir gently until combined.
In a separate bowl, beat egg whites on high speed until soft peaks form. Gradually add remaining 1/4 cup sugar and beat until stiff peaks form. Fold egg whites into the batter gently until just combined. Pour batter into prepared pan.
Bake for 25-30 minutes, or until a toothpick inserted into the center comes out clean. Allow to cool completely.
In a small bowl, whisk together evaporated milk, sweetened condensed milk, and whole milk. Pour over the cooled cake.
In a large bowl, beat heavy cream with sugar and vanilla until stiff peaks form. Spread over the cake. Refrigerate for at least 1 hour before serving.
Notes:
For best results, refrigerate the cake overnight to allow the milk mixture to fully soak in.