Preheat oven to 350 and grease 2 7-inch cake pans or whatever size you would like. This cake can also be made into layers as I did in the photo.
In a medium bowl, sift together all-purpose flour, baking powder, and salt. Set aside. In another medium bowl, whisk together milk, egg whites, vanilla extract, and rose water.
Place butter and sugar in a large bowl. Using a stand mixer or electric mixer, cream together the butter and sugar until light colored and fluffy. Scrape the bottom and sides of the pan while you go to make sure it is well mixed. This will take around 5 minutes.
After creaming the butter and sugar, add about 1/3 of the dry ingredients to the creamed mixture. Mix well. Next add 1/2 of the wet ingredients. Repeat until you finish with the last addition of dry ingredients.
Pour the batter into your greased cake pan(s) and bake for 15-20 minutes. I baked two 7-inch layers and I baked them for about 12 minutes, oven time may vary a bit depending on your oven.
Cool cake completely on a wire rack before icing.
To make the icing: in a small bowl, sprinkle gelatin over cold water to bloom and let sit 5 minutes. Add hot water and stir to melt the gelatin. In the meantime, whip your cream to medium peaks and pour in gelatin mixture. Whip to medium-stiff peaks.