Preheat oven to 350 degrees F (175 degrees C). Grease and flour one 9x13 inch baking pan.Sift flour and baking powder together and set aside.Cream butter or margarine and the 1 cup sugar together until fluffy. Add eggs and the 1/2 teaspoon vanilla extract; beat well.Add the flour mixture to the butter mixture 2 tablespoons at a time; mix until well blended. Pour batter into prepared pan.Bake at 350 degrees F (175 degrees C) for 30 minutes. Pierce cake several times with a fork.Combine the whole milk, condensed milk, and evaporated milk together. Pour over the top of the cooled cake.Whip whipping cream, the remaining 1 cup of the sugar, and the remaining 1 teaspoon vanilla together until thick. Spread over the top of cake. Be sure and keep cake refrigerated. Enjoy!