This tutorial will show you the most basic and least equipment-heavy way of baking the concentric layer cake as seen in both the Earth cake and Jupiter cake.
For more tips on baking this cake and for the four recipe used in this video, head to the blog post at Cakercrumbs:
[ETA: Sooo. A lot of sites are linking to this video saying it will show you how to make a Jupiter cake. It absolutely will not. It is only a video showing you how to bake concentrically layered sphere cakes as the title says. I made this cake to answer the question of how I made my Earth cake and figured I’d use the opportunity to experiment with my painting skills. Not only did I not document the process, I completely made it up as I went along and changed my method of doing so thrice throughout. So there’s nothing on painting fondant in this video, but I’m working on a fondant painting tute to explain my current go-to technique.]
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