Right, due to popular demand; here is the tutorial for the Lego cake. Now I have to admit, there were some issues with this cake in terms of it's construction, and I think future versions would require quite considerable engineering work to ensure it remains stable (and survives a car journey, unlike my original attempt!) I would recommend using dowels and base boards for the individual cakes as you would with any stacked cake. Why this didn't occur to me initially, I'll never know!
Start by making a tray bake sized cake (or whatever sized cake you require). This was a 3 egg recipe. Once cooled, cut the edges to give you nice corners and straight sides, then split horizontally into two halves.
Put raspberry jam on one half, and buttercream on the other half, before sandwiching them together.
Next comes the mathematical bit! You have to use your judgement, and try out a few circular cutters to make sure you get the most 'bricks' out of your cake as possible. I used a 1.5 cm diameter cutter to help me mark out the bricks in the top of the cake, scoring where I'd need to cut.
Next the cakes are cut into individual bricks. I found it helpful to have some Lego bricks with me to use as a guide, so that they would look proportionally accurate.
As the cake had risen slightly more in the middle than on the edges I used some of the cake trimmings to try to build up the slightly slanting edges of some of the bricks, by placing slivers into the filled section of the cake. I'm not sure if this made a great deal of difference I though it best to make things level from the start.
Once you're happy with your cake shapes it's time to cover with buttercream. I used quite runny buttercream and applied it with a pallet knife to try to get a smooth covering. It's inevitable that crumbs will mix into the buttercream, but try not to manipulate it too much as bits of the cake (i.e. corners) might come away from the cake.
Next came the detail on top of the bricks. I opted to create this by cutting out circles using my chosen cutter, from fondant icing rolled to around 8mm thick. I initially rolled my icing out too thinly so doubled up on my 'dots'.
The dots are then placed in position on top of the covered bricks. They should stick nicely to the buttercream. I used a cake smoother to press them flat into the buttercream, and again to try to make them level, but this is optional.
Once I was ready to roll out my chosen icing to cover the bricks, I painted each of the disks with boiled water to create a 'glue' between the two layers of icing. I chose primary colours for my bricks.
I ended up covering bricks in two different ways, so feel free to try whichever works best for you. The first way was rolling the fondant flat, quite thinly (around 3-4mm), draping this over the brick, then guiding it over the dots and down the sides and corners.
This did create a puckered corner, which needed to be smoothed with a tool and patched up using boiled water and icing sugar.
My next attempt was to roll the icing equally thinly, but this time cutting into the shape to create slightly overlapping sides, which avoided the bulk of icing at the corners.
I measured the top of the brick, then allowing an edge of around 5mm, cut darts into the corners.
These pieces of fondant draped nicely over the bricks, and I found that it was easier to smooth the cut corner seam, rather than patch up the corners where the fondant had folded.
Once the bricks were covered it was time to prepare the board. I cut out various shapes and colours for the tops of bricks, and stuck cut outs of the dots on to the top. This actually looked really effective, and I think I would consider using this method for the bricks if I was to do this again, as it gave more definition.
The bricks were then places on the board. I mentioned at the beginning that there were structural issues with this cake. The final version involved a separate 2-dot brick being provided in it's own box, which was then placed on top at the last minute.