Make the cake. If using a traditional buttercream, leave a thin, very cleanly done crumbcoat. For best results, freeze cake. Entremet or mousse cakes are best as the finish is smooth and the glaze will highlight all imperfections.

Bloom gelatin in the 80g cold water. Allow to sit.

Boil the 100g water, sugar, glucose in a saucepan over medium heat until fully dissolved. Remove from heat and add in gelatin.

Add the condensed milk to the mixture. Pour entire warm mixture over chocolate. Allow to sit for 5 minutes.

For best results, use an immersion blender to combine until perfectly smooth and shiny. Alternatively, you can stir carefully. Check the temperature of the mix. Use when the temperature reaches 32°C/90F. This is important to not get to correct texture and pour. It may take a while to cool. Stir carefully while waiting and ensure you use a thermometer.

When ready to glaze the cake, cover a surface or rimmed baking sheet with plastic wrap for easy cleanup. Use a large glass to place the cake (keeping the bottom of a spring form pan or small plate on the bottom of the cake) above the pan. You want to be able to pour and have the excess glaze run off.

You can colour the glaze in individual containers with gel food colouring. Have all of your colours ready and at 32°C before starting. They will maintain temperature for a decent amount of time, but you will want to work quickly. To get a gradient or different colour design, pour the base colour completely around the top of the cake. Use plenty to cover all areas. Then, immediately pour on the other colours.

To finish, take a long offset spatula and hold it perfectly level to the top. Swipe the spatula across the top, just barely above the cake level to remove excess. This will leave your finish looking flat and perfect. Allow to sit before moving cake. Rest to set. You may refrigerate before serving.

Let glaze drip about 10 minutes, then clean up edges with a small offset spatula or butter knife. Transfer cake to a serving platter and chill at least 30 minutes or up to 1 day.