Bloom gelatin:When using gelatin powder: Sprinkle it in icy-cold water in a small bowl, mix well, and let it sit for about 10 minutes to let it hydrate completely.When using gelatin sheets: Soak them in icy-cold water for about 10 minutes.

Heat water, sugar, and corn syrup:Add water, sugar, and corn syrup to a medium-small saucepan. Heat it at medium heat.Mix it with a rubber spatula while heating, especially toward the end, to prevent the liquid from overfloating.Remove from the heat once it reaches 217ºF (103ºC). I usually don't use a digital thermometer, but judge by the look instead: Remove from the heat once it starts bubbling hard.

Add condensed milk:Add sweetened condensed milk to the hot liquid and mix until combined. (You could heat it with other liquids in step 2, but I decided to add it here so that I can cool the liquid just slightly before adding the gelatin since some gelatin could lose some of its strength when it's added to boiling-hot liquid.)

Add bloomed gelatin:Add the bloomed gelatin to the hot liquid and mix well until it dissolves completely.

Combine it with white chocolate:Pour the hot liquid over the white chocolate in a large bowl. Mix until combined.At the end, emulsify the chocolate with a hand blender.Be careful not to lift it too while blending it to prevent it from containing lots of air bubbles. Lean it over slightly, like in the image below, instead of holding it straight to remove the bubbles more easily. As an option, add food coloring to make different colors.

Prepare all the tools and a cake:Set up all the tools and a cake ready while the glaze is cooling down so that you can quickly pour the glaze over the cake once it reaches the ideal temperature. Preparing it well ahead also gives you more ease and confidence to do it successfully! * A wire rack on top of a baking sheet lined with plastic wrap.* Another baking sheet (lined with plastic wrap)* Off-set spatula* Remove the frozen cake from a silicone mold or cake ring and ensure that it is completely frozen. (If it might take a while to freeze a cake completely in your fridge, consider making it a day before.)* Select a plate or cake board to which you want to transfer the cake.* (Decorations for the cake)

Let the glaze cool:Let it cool to 86 - 95ºF (30 - 35ºC). The exact temperature depends on the freezer, the room temperature, how fast you can move, and so on. With my freezer, it usually works the best at 91ºF (33ºC).

Pour the glaze over a cake:Once the mirror glaze reaches the temperature, immediately pour a generous amount of the glaze on top of the cake in a circular motion so you can coat the sides of the cake all around. Next, immediately stroke the surface of the cake with an offset spatula to drop excess glaze and make it thinner. Move the spatula parallel to the cake to create an even layer. This process also helps glaze over any uncovered spot on the side, if there is one.Be careful not to scrape off the surface too deep. You'll only need to stroke it slightly.

Transfer a cake:Lift the wire rack and move it to the second tray. (That is because I don't want the mousse on the bottom to get scratched and go in the leftover glaze in case I want to use it again.)Wait for seconds until you do not see that the glaze is no longer dripping on the bottom:Insert an offset spatula under the bottom and move it in a circular motion to cut off the dripped glaze. It'll give you a nice sharp cut on the bottom edge: As a final step, transfer the cake onto a plate or cake board!Check out the video tutorial to see how I transferred the cakes.