How To Make A Sailor Suit Onesie Cake

Looking for the perfect Baby Shower cake for a boy?...well look no further than our Sailor Suit Onesie cake tutorial. This cake is perfect for a Nautical themed baby shower or works just as well on it's own as a centerpiece for a party strung with simple blue decor. Although this cake looks impressive, it's easy to make because it starts with our inexpensive onesie shaped pan. No muss no fuss, you're already half way there. Instead of covering the cake entirely in rolled fondant, we opted for nubby buttercream piped texture to give our onesie a soft knitted look, although this cake would work just as well with smooth icing if that's your preferred approach. Simple fondant accents bring the whole look together and add some crisp graphic elements to tie the nautical look together.

RECIPE NOTES: Our onesie pan uses one box mix of cake or if you prefer to go from scratch (we do), check out our Vanilla Cake Recipe as a place to start. You will also need a tasty buttercream recipe suited for piping and large enough to cover the entire cake. We recommend our Brenda's Bakery Buttercream Recipe and you'll need to make a 1 1/2 batch to have enough for piping.

Availability: In stock

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Baby Onesie Shaped Cake Pan
Fat Daddio's Red Rolled Fondant Icing - 8oz
# 8 Round Decorating Tip
Fondarific Blue Rolled Fondant - 8oz

Regular Price: $5.95

Special Price $3.57

3/4 oz Sky Blue Gel Paste Food Coloring
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Grease and flour your pan and bake the cake according to your box mix or our Vanilla Cake Recipe instructions. Once cooled, wrap your cake in plastic wrap and refrigerate for a few hours to chill in order to make icing it easier. Prepare your 1 1/2 batch of Brenda's Bakery Buttercream. Tint 1/3 of your buttercream light blue.

Onesie Shaped Cake Pan

How to make Buttercream for piping


Crumb coat your cake and use a toothpick to draw out a triangle on the chest and a line where the waist band will go so you'll know where to pipe later. Fill your piping bags and fit them with #8 piping tips.

Pipe icing in the triangle, leg holes and arm holes and use a spatula to smooth these areas out.

Crumb Coating a Onesie Cake

Sailor Suit Onesie Cake

Sailor Suit Onesie Cake

Pipe rows of dots on the rest of the cake to create the texture. These don't have to be in perfect rows, you're just trying to add a knitted look to the cake.Chill your cake while your move on to the next few steps.

Piped Onesie Cake


Roll out ropes of red fondant and line the leg holes and the chest triangle of the onesie.

How To Make A Nautical Onesie Cake

Then, roll out some dark blue fondant with a rolling pin, about 1/4" thick and cut two large triangle for the collar. You can use a ruler to measure how long you need the collar to be (although we just eye balled it). Most importantly, make sure your triangles match each other so they don't look lopsided. Use the first triangle as a template on the fondant to cut the second triangle out so they match.

Blue fondant triangles

How To Make A Sailor Suit Onesie

Roll a red ball for the knot and press it into the cake. Then, cut out two football shapes from some rolled red fondant for the bow tails. Pinch the ends of the bow tails before adding to the cake to give them character.

Roll two little balls and flatten them for the buttons. Use a toothpick to make 4 holes in the buttons and then attach them to the belt with a dab of water.

How To Make A Onesie Cake For A Boy

To complete this cake, pipe a white line of buttercream on the edge of the collar with a #3 piping tip (although I think this is totally optional).

Ahoy! This cake is done! Wow...time to watch your guests oooh and ahhh.

How To Make A Onesie Cake For A Boy

How To Make A Onesie Cake For A Boy