Monsters Inc Birthday Cake – DIY

Monstes Inc Birthday Cake

For Joshua’s 3rd birthday party, he requested a Monsters Inc theme. Right away, I jumped online to find some cake ideas. All of the Monsters Inc birthday cakes were absolutely adorable. I showed Joshua his options and he immediately chose Mike Wazowski sitting on top of a Sulley cake. He pointed at the picture on the computer and then looked over at me and in his cute little voice said “Mommy, I love that cake but can you please make Boo for me too?” A Monsters Inc Birthday Cake just isn’t complete without Boo, so of course I said yes.

SEE ALSO: Monsters Inc Birthday Party Ideas & Disney Frozen Birthday Party Ideas

If you’ve read any of my previous party posts, you know that I get pretty into party planning. I actually take the day before my boys’ birthday parties off from work so I can focus on prepping for the party and making the cake. I usually make a 1/2 sheet cake for my boys’ birthday parties but the cake Joshua wanted was two layers and the top cake was completely covered in fondant. I add fondant to all of the boys’ cakes but I usually just make figurines with it. I’ve never actually wrapped a whole cake in fondant before so this Monsters Inc birthday cake was going to be interesting.

Baking Joshua’s Monsters Inc Birthday Cake

Monsters Inc Birthday CakeBy 7:30am, on the day before Joshua’s party, I had three boxed cake mixes in the oven. Two 9″ round cake pans each held a box of milk chocolate cake mix. I used the Wilton Sports Ball Pan Set to make the Mike Wazowski cake. This was filled with one box of Funfetti cake mix. Once the cakes were done, I took them out of the oven and let them cool completely before removing them from the pans. I then stacked the two 9″ cakes, and the two halves of the ball cake, filling the middles with butter cream frosting. I always make my own frosting and have used this recipe from for years. Everyone loves the taste of this frosting and I love working with it. After stacking the cakes, I covered both of them with a thick crumb coat. I placed the round cake in the fridge to help set the crumb coat and I placed the ball cake in the freezer so it would be easier for me to work with it while trying to cover it in fondant later.pickease_web_ebook-cta-(640).v1a-02

Making Boo 

Monsters Inc Birthday Cake - BooAs I said earlier, Joshua really wanted Boo on his Monsters Inc birthday cake. I could have just put one of our Boo toys next to the cake but I like to challenge myself just to see what I’m capable of so while my cakes were setting, I started working on making a fondant Boo. I started by forming an oval shape out of my fondant to use as the base of Boo’s body. I didn’t bother coloring this piece because I was going to eventually wrap it with Boo’s costume. Next, I colored some fondant peach and rolled a ball for Boo’s head. I pinched the sides of the head out a bit to make her ears and rolled a little ball for her nose. I then colored some fondant black and wrapped it around the top of Boo’s head to make her hair. I pinched out the sides for her pony tails. I colored a small amount of fondant red to make her pony tail holders. I just used water as my “glue” to hold everything together and attached Boo’s head to her body with a toothpick for some extra support. Next, I colored some fondant purple for Boo’s costumes. I rolled it out flat and then painted water on her body and wrapped the purple fondant around it. I used scissors to cut off the extra fondant and then wrapped that around her head to make the hood of her costume. I used plain white fondant to form Boo’s arms, legs, and the teeth, hair and eyes for her costume and again, attached everything with water as my “glue”. Finally, it was time to add the details. I use the Wilton Paste Tool Set Delux for all my fondant needs and made all of the little details with the tools from that kit.

Making Mike Wazowski and Sulley 

Monster Inc Birthday CakeNow that Boo’s finished and my cakes have set, it’s time to make Mike and Sulley! I started by coloring a large amount of fondant lime green (the color of Mike Wazowski) and rolling it flat. Then, with my ball cake sitting on top of an upside down plate, I frosted it with fresh buttercream frosting. Once the ball cake was frosted, I carefully lifted up my fondant and placed it over the cake. I smoothed the fondant over the the cake, trying to work out the wrinkles as best I could. I then cut the extra fondant at the bottom of the cake off, leaving the underside of the cake uncovered. I then covered my 9″ round cake with a thin layer of fresh buttercream frosting. I stuck three wooden dowels in the center of the cake and then carefully placed the ball cake on top of the round cake with the dowels going through the middle of it. Once I had the two cakes together, I added Mike’s legs. I simply rolled green fondant into two long snakes and placed them over the bottom cake. I colored half of my remaining buttercream frosting teal and the other half purplish-pink. I piped on Sulley’s fur using Wilton’s No. 233 Multi-Opening Decoration Tip. The majority of the cake was teal and the spots were purple/pink in the pattern of Sulley’s fur. Next I started on the details of Mike Wazowski. I rolled out white fondant and cut it into a circle shape for Mike’s eye and then rolled some green fondant snakes for Mike’s eye lid. I then rolled out some black fondant and cut it out into a smile shape for his mouth. I attached everything to my green ball with water. I then started shaping his teeth with white fondant and attached them to the mouth once I was finished. I rolled out two more green snakes and attached them to the mouth for Mike’s lips. Next I made Mike’s arms, hands, and feet. I placed white fondant on his fingers and toes for his nails. Lastly, I made two horns and a blue eye. I was so proud of myself for being able to make this cake for my littlest love. He absolutely adored it and all of our party guests were really impressed. I hope this Monsters Inc Birthday Cake tutorial helps you! If you decide to give this a try, please be sure to share pics of your Monsters Inc Birthday Cake!

Monsters Inc Birthday Cake

Monsters Inc Birthday Cake