Bloom gelatin in cold water, remove from water once soft and reserve in a bowl. Place water, sugar, and sweetened condensed milk in a pan and bring to a boil. Remove from heat and stir in gelatin until it melts. Pour hot mixture over white chocolate and let it set for 2 minutes, stir to melt, using a burr mixer if needed, being careful to keep it totally submerged so as to not get air bubbles in the glaze. Any air bubbles in the glaze in the bowl may come out in the finished product. Divide glaze into 4 different bowls. Color one blue, one burgundy, one white, and one pink taking care to stir slowly and not add additional air. Let glazes sit at room temp, stirring gently occasionally so they do not develop a skin until they all are between 92F and 96F. It is extremely important that all the glazes are the same temperature and that they are all in the correct temperature range.
In a stand mixer fitted with the whip attachment, Sponge Cake Base, water, and eggs on 1st speed for one minute. Scrape down. Whip batter six minutes on third speed. Spray and paper an 8” round cake pan and deposit 12 ounces batter in 2 pans. Bake until golden brown and cake springs back lightly when touched. Let cool completely.
Mix together equal parts by weight sweetened condensed milk, evaporated milk, and half & half. Weigh cake pour the same weight prepared milk over cake and let soak in completely. Place one cake round on a cake board, and fill with Vanilla VelveTop. Be sure to use a cake board that is slightly too small for the cake to help with glazing. Place the other round on top and crumb coat with vanilla VelveTop. Freeze overnight.
Make Mirror Glaze. Meanwhile, set up a cake ring slightly smaller than the frozen cake round on a glazing screen with a sheet tray beneath it. Pour each of the glazes into a large pitcher. Take the frozen cake out of the freezer and set on top of prepared cake ring. It is important that both the cake board and the ring are smaller than the frozen cake so that the glaze can drip down the cake evenly. Pour the glaze in the center of the cake until it completely covers the sides and top. Let set for a moment as the excess glaze will need to run off. Place glazed cake onto a larger cake board and refrigerate.