Preheat oven to 350 degrees
Combine cake flour, baking powder, salt and 1 cup sugar in a mixing bowl and mix well.
Add in oil and 3/4 cup milk. Beat together. It'll be really stiff.
Add in egg yolks and 1/4 cup milk and vanilla. Beat that until smooth. (Should be quite thin.)
In another bowl beat up your 5 egg whites until stiff and slow add 1/2 cup sugar and beat until it turns to a stiff meringue. The fold the cake flour mix into the egg whites. (Don't beat it - just fold it in.)
Bake in a preheated oven until top is golden brown or a toothpick into the middle comes out clean. Works well for cupcakes (13-15 minutes) or round cakes (20-23 minutes).