I'm pretty proud of this one. I finally cracked tempering chocolate- something that's been on my to-do list for a while- to make the chocolate garnishes. In person they're all lovely and glossy.
I made this cake based on my strawberry mousse cake recipe, but with mangoes instead of strawberries (but you've already figured that out), and finished with a shiny mango mirror glaze using 1tsp kosher gelatine, 100g puréed mangoes, 1tbsp caster sugar and 2tbsp water.
I did make some changes though in order to make the presentation right: I scaled the Genoise sponge recipe down to a 2-egg recipe and used a smaller springform tin, and trimmed the cake around the edges so that the mousse would show all around the sides. As for the mousse, I kept the original quantities largely the same (I needed enough mousse to fill the middle AND cover the sides and top), but cut the cream from 300ml to 200 ml for a slightly firmer mousse.
Also, in terms of presentation and getting the cake out, I did two things differently: instead of lining the tin with foil, since the tin was already deep and I made a smaller cake, I simply greased the sides with oil. I cut out a disc of sturdy cardboard big enough to fit snugly inside the tin, lined it with foil and, once the cake was baked, placed it at the bottom of the clean tin before re-assembling the cake. I think I'll do this from now on when making this sort of chilled cake- it definitely takes a lot of stress out of transferring the cake later.
For the smoothest edge, I chilled the mango mousse cake in the fridge for three hours, chilled it for a further two after pouring over the mirror glaze, and transferred it to the freezer for one hour. Then I ran a hot knife around the edge to loosen the sides before unclipping the springform and lifing the cake on its foiled cardboard base onto a plate. I re-heated the knife by dipping it in hot water and wiping it dry, and swiped it around the side of the cake for the most perfect smooth edge.
Lastly, this time I made it in time to bother letting it stay in the fridge overnight before serving. It really makes a difference in terms of letting the gelatine settle.