In a saucepan, combine 80g granulated sugar and 1 tbsp water, and heat until the sugar turns golden brown.
Pour in 80ml warm water and bring it back to a boil, then remove from heat.
Stir in 40g condensed milk, 80g glucose syrup, and 5g bloomed gelatine.
Add 60g white chocolate and stir until melted and smooth.
Sift the glaze into a cup and cover it with plastic wrap, pressing it down to touch the glaze.
Let glaze cool to 27°C before pouring over the cake.
Remove the mousse cake from the freezer and carefully remove the acetate sheet.
Gently pour the cooled caramel mirror glaze over the mousse, starting from the center and working out to the edges.
Use an offset spatula to smooth and clean up excess glaze from the bottom.
Refrigerate for at least 2 hours to set the glaze.