Now, I am no professional baker - and I'm sure my methods are not the 'true' methods, but Little B loved it, and that is all that matters to me :)
So this is the finished cake -
And this is how I got there -
First off I baked four cakes - I used a basic Victoria sponge recipe and made two 23cm rounds and two 18cm rounds (no reason why I did those sizes - those were just the size cake tins I had!!) - and I decided to make the inside more interesting and make the cakes pink and purple!
Let theses cool completely before doing anything with them - I put mine in the fridge overnight.
For the bottom layer I just had the two 23cm rounds stacked, and for the top semi circle layer I cut my two 18cm cakes in half - but decided to only use three of my halves, as all four would have been a bit too high.
The next morning I did the butter icing coating - for these cakes I made up 500g of icing sugar with a 250g pack of butter and added a splash of milk - and I used up the whole lot!
So the aim is to get everything as flat as possible - see in the picture above I have trimmed off the worst of the domed bit in the middle of the cake - you don't need to go all the way to the edges because the butter icing will fill in a little bit.
With a piping bag I first squeeze some butter icing in a big ring around the edge, then fill in the bit in the middle - smooth flat with a pallet knife, then drop cake number two on the top (I put mine bottom up - because the bottom is a bit flatter) and give it a little squish! Continue with as many layers as you have.
At this point I don't worry too much how smooth it is because the soft butter icing is quite hard to get super flat - I put the iced cakes in the fridge for the rest of the day to harden up.
Later that evening when the butter icing has set I do a combination of scraping and filling in with a pallet knife and some fresh icing to get everything really smooth and the corners all nice and sharp - occasionally I will put the cake back in the fridge then have another scrape until I'm totally happy! Then it all goes back in the fridge overnight again.
Next up is the fondant layer - I buy a big pack of white fondant, then use gel colours to mix the colours I want - in this case I did green for the bottom layer and blue for the top. Make sure you use plenty of icing sugar when mixing and rolling to stop sticking!
For the blue layer I rolled out a big semi circle about 5mm thick - I put it over the top of the cake and used a fondant smoother to get all the bubbles out - starting at the top then working down the sides - for the sharp corners either side I bought the fondant together and pinched it, then used a sharp knife to trim away the excess.
For the green layer I did the same thing - starting at the top with the smoother, then working down the sides, and finally smoothing the fondant right onto the cake board (I put a little smear of butter icing on the board first to make it stick).
Once again it's time to wait - the fondant will go all sticky from the coldness of the cake (fondant and cold don't go well together!), so you need to let it all come to room temperature and the fondant will dry out - I covered mine in the morning, and by the evening they were ready.
Next I stacked the cakes - I stuck a few straws in the bottom layer, cut them off at an angle, then slid the top layer on.
Next I built up my decorations - a tunnel for the train to come out of -
And bushes -
And some tracks and clouds -
And it was yummy!!
Just in case you you thought I'd stopped sewing to bake cakes, I didn't!! I also made Little B a party outfit - a tunic and leggings with a matching hair band, and Little Fizz got a reversible waistcoat and matching trousers - he looked so smart!! Here's B in her outfit -
And Fizz -