Step 1: Ingredients and Tools
Buttercream is the usual crumb coat but research told me that ganache works too which was great, because 1.) It tastes amazingly good and who can have too much chocolate and 2.) I made way too much to use as just the filling. You’ll need a cake: You can use a cake mix, any flavour you like. Or you can make a scratch cake.
I made an orange pound cake using this recipe: http://food.com/recipe/barefoot-contessas-orange-pound-cake-144654
You could bake it in 2 square cake pans, in a 9 X 13 cake pan or, as I did, two loaf pans - as long as you can eventually cut it into 8 squares.
You will need a filling to stick layers together. I made a chocolate ganache using dark Belgian chocolate, whipping cream, grated orange zest and agave syrup. Any good ganache recipe will work. Alternately, you can do butter cream icing. There are hundreds of recipes and instructions out there for ganache and for buttercream if you Google.
You will need an icing to cover the cakes. This is called the crumb coat because its job is to glue the crumbs to the cake so they won't ruin your icing. This also works as the glue that holds the fondant to the cake.
You will need fondant and gum paste to decorate. Gel food colouring is really the way to go to add colour. A few tools like a rolling pin, an off-set spatula, a fondant smoother (looks like a little plastic iron) and cake racks make the job easier, but you can get by with stuff you already have until you decide you might want to do this again. To make this cake, you also need a set of letter shaped cookie cutters.
Step 2: Bake the Cakes
If you've used two square pans, just cut each cake into quarters. I used loaf pans and after cutting off the domed middle, I cut them horizontally into two layers and then cut each layer in half.
Cool the layers spread the filling over the layers and sandwich them together to make four relatively cube shaped cakes.
Cover the outside of each cake with buttercream icing or - as I did - with more ganache. Try to smooth them as smoothly as possible. The neater you are with this step, the easier the next steps will become.
Make room in your fridge and refrigerate the cakes.
This was as far as I went the first day. It took me most of one Sunday afternoon. If you're going to do it all in one day, you've got another 3 or 4 hours work to go.
Step 3: Gum Paste
I bought the gum paste powder. One pound of powder and a quarter cup of water, a few minutes kneading and I was ready for colour. I decided on 5 colours since each cake would have 5 visible sides needing a letter each.
I cut the prepared paste into 5 roughly equal balls. Using a tooth pick (the tool of choice for gel food colour), I added a little colour to the first ball. I wore latex gloves to do the mixing. The colour does wash off but it might take a couple days to get rid of all staining.
Knead in the colour on a board using a dusting of icing sugar to keep it from sticking. You can always add another dab of colour if you find it's still too pale. As I finished each colour, I dropped the piece in a small plastic bag to keep it from drying out.
Step 4: Cutting the Letters
I had put a piece of parchment paper on a tray and I placed the letters there to dry as I finished them.
Once dry, I used a pastry brush to take off as much of the extra icing sugar as I could.
Step 5: Covering the Cakes With Fondant
One pound of fondant is enough to do the four cakes. Open the package; knead the whole piece until it is pliable and smooth and workable. Next, cut it into 4 roughly equal pieces and one by one, roll them on the board, again using the icing sugar to prevent sticking.
Once the piece is larger than necessary to cover the cake and drape down all four sides, lift it carefully by putting two hands underneath, letting the fondant drape softly over your hands. Hold it carefully above the cake making sure you are centered. Once you drape the fondant on the cake, there's no going back. If you make a mistake and take it off, you'll need to start with a whole new piece.
Place the fondant on the cake and smooth the top, pull it gently down on each side. Pull out the piece poking out at the corner, pinching it together, smoothing the two sides toward the corner. You will cut down the pinched out piece with a pair of scissors, going as close as possible to the corner. Once the extra is cut away, smooth the two sides and press the corner seam together.
Do this on all four corners. Finally, with a sharp (paring) knife, trim the excess around the bottom of each side. Use the little fondant smoother or the palm of your hand to keep working the fondant until you are satisfied that it is smooth and even.
Place the finished cake on the parchment and repeat 3 more times.
Step 6: Painting the Cakes
Out come the gel colours again but this time they need to be thinned out.
I hope you happen to have a handy shot of vodka now because that is the ingredient of choice. Gin works too and so does Saki which is what I happened to have on hand.
Another toothpick's worth of gel mixed with about a tablespoon of spirits makes a very good paint. The alcohol evaporates more quickly than water so your fondant doesn't get all soggy and droopy before the paint is dry. You won't taste the alcohol, honest. It's all evaporated long before you eat the cake.
I mixed up three colours mainly because I found three paint brushes, and painted the cakes.
Step 7: Gluing on the Letters
Make up some glue - take a tiny scrap of gum paste and put it in a bowl with a teaspoon of water (or vodka!) Rub it between your fingers until it dissolves. The mixture will have a sort of slimy feel, just like glue!
I made sure I had cut out two B's, one A and one Y. I glued them on the four different cakes to spell out baby when they were set out on the tray. After that, I just made sure I had one letter of each colour on each cake.
Using my (cleaned) paint brush, I painted the back of each letter and pressed it onto the cake. I also brushed the outside of the letter to make it shiny.