This cake is also called “death by food colouring,” but only on the inside.
I’ve never done a 6-layered cake before — I divided two white cake mixes into four batches using my kitchen scale. For each batch, I added extra flour, some eggs whites & oil and soda water (a variation of http://www.cakecentral.com/recipe/7445/the-original-wasc-cake-recipe), then split it into two bowls and coloured them. After baking all the layers, I used thick buttercream as a dam and filled them with cream cheese & whipped cream icing.
I cut around the edges of the cakes, since they weren’t flat, and weren’t tall enough to level.
Then I used a big tip to crumb-coat it. That tip saved the cake, because the layers were too crumbly and kept threatening to break off!
I put it back in the fridge after getting mad at it a few times, then when the icing cooled down, I was able to smooth it out a bit.
After that it was relatively easy! I used my Russian tulip tip for the flowers, a ziplock bag for leaves, and the normal whatsit schloopy tip for the borders.
I’ve decided I like the lines, instead of smoothing it out completely — it kind of says, “I’m not fondant, I’m buttercream!” which is nice, since I don’t really like fondant.