The cool thing about this cake is that it's very customizable, you can pick any type of octopus to model it after and you can also very easily make it bigger or smaller. Let's get started!
Step 1: Supplies
6 cups buttercream
4 lbs fondant (I used satin ice, but any brand will work, or even homemade)
A small amount of Gumpaste (optional, I only used it for the tips of the tenticles but that could also be done with fondant)
Pastry wheel/fondant cutter
Airbrush and compressor (optional, you can always just hand paint it as well)
Airbrush colors if using
Food colors that match your chosen octopus ( I went with reds browns and yellows)
Vodka (for mixing paints)
Food writers (if you don't like painting fine details these are a great alternative)
Paint brushes (regular paint brushes are fine but just make sure you designate them for food only)
Rice Krispy treats (store bought or homemade both work, I used a combination of the two)
18" cake board
Brown sugar for sand
Step 2: Prepare the Cake and Buttercream
I just used a standard homemade all butter buttercream to crumb coat the cake. Any recipe will work or you could also use store bought.
For the fondant I used satin ice because of time and because I usually make marshmallow fondant which is by nature much softer and wouldn't work as well for this complex of a design. You could definitely use any other brand or homemade fondant if you would prefer.
Step 3: Fill, Frost, and Carve
Next your going to need to cut the other three cakes into a moon shape. I just used my 8" pan to do this but cutting it to be about the length I wanted my front two tentacle bases to be. You will have a good amount left over but save that for later.
Once you have that done you are ready to start carving. I started by carving the center 8" to be more round, I then cut a v out of the moon cake and carved them down to the shape I wanted. Always start slow carving small pieces at a time until you get your desired shape.
After that I took the leftover cake scraps and put them in a bowl with some frosting to make a cake pop batter. I used that to make the eye structure and some of the tentacle. This is really helpful if you want rolled tentacle and to give you a base to build onto with the rice krispy treats.
The last step is to crumb coat the cake with a thin layer of buttercream making sure to cover everything.
Step 4: Tentacles
I just kept rolling out different sizes and lengths of rice krispy treats to make the tentacles, attaching them as I went until I was happy. To make them stick up I balanced them on other tentacles to give them more of a realistic feel.
I then covered all the tentacles in buttercream.
Step 5: Cover the Cake
After that i rolled out some leftover fondant to cover any parts I missed with the first covering. Using small pieces I filled in all the gaps and smoothed it with a little water to make the seams disappear.
Don't worry if the fondant isn't perfect. All of the imperfections will most likely be covered once you paint it and add all of the details.
Step 6: Paint the Cake
Next comes the airbrushing, or painting if you don't have an airbrush. As you can see I did several coats to get the color I wanted starting light and going darker to give it more depth.
Then I did the tentacles. I hand painted them because I wanted a cleaner line than I would get with the airbrush but you could definitely do it that way too. I went with I pale dull pink to start making it a little darker because I knew I was going to go over it. I then airbrushed the whole octopus with a yellowish brown to make it all blend together.
To make the eyes I dyed some fondant yellow and made two balls and stuck them in with edible glue. I also airbrushed those with the yellow brown that I made for the whole octopus trying to really highlight the edges.
Step 7: Final Details
For the eyes I used black food color thinned with vodka and painted a crescent type shape to make the pupils.
The last thing I did was adding brown sugar around the octopus to look like sand, and there you have it!