Coolest Sponge Bob Birthday Cake

I made this Sponge Bob birthday cake for my God-son and his Grandpa. They share the same birthday. My God-son loves Sponge Bob and the idea came from a Sponge-Bob episode.

The Cake:

I used 2 boxes of white cake mix and doctored them up. To each cake mix I added: 4 eggs, 1cp. plain vanilla yogurt (lowfat), 1cp. sour cream, 1/2 cp. water, 1/2 cp. oil (vegetable), 1 pkg. instant vanilla pudding (3.2 oz.). Mix all ingredients until smooth (the batter will be thick). I used 2 13×9 baking pans. Bake cakes @ 350 for 20-30 min. (depending on oven). Completly cool and freeze or refrigerate. I froze my cakes over night. I cut the edges off the cake to make a perfect rectangle (a ruler helps to get the lines even and straight, while cutting).

I stacked the cakes. I put strawberries and homemade whipped cream for the filling. I took out about 1/4 of an inch of cake from the top, leaving a little circle for the island (leave edges thick so it’s easier to apply icing without the edges braking).

This cake recipe is by far one of the best to create themed cakes with. It cuts clean, not a lot of crumbs and stays very moist (you can use a yellow cake mix too! Use the same ingredients listed above, but add 1 tbsp. of vanilla extract).


I crumb coated the cake with whipped cream icing (not a good idea). It was difficult to keep cold and decorate. I left the whipped cream icing on and made a buttercream icing with blue gel (just a little blue gel in white icing makes a light blue). I then frosted the whole cake with the buttercream. I was pleased with the texture and how the cake looked

(mistakes can be a blessing).


I purchased the Sponge Bob character from my local bakery (inside the grocery store). The island, I used crushed graham crackers and a tiny bit of brown sugar to look like sand. The umbrella I purchased a pack at my local dollar store. The treasure chests are made with 2 Hershey’s chocolate nuggets. I put a dab of butter cream frosting on the bottom of the nugget and then put gold pearlized sprinkles. I put a line of frosting on both edges and attached them (make a day before so they have plenty of time to dry and don’t move them until dried. They will fall apart.)

For the water I used blue Cake Mate Decorating Gel (4 tubes). The bubbles I used butter cream as well and made it a deeper light blue, with the blue gel. I made this icing a thicker consistency. I used the bubbles to cover up the imperfections too! For the writing I used the same icing as the bubbles, but colored it with yellow gel to stay with the Sponge-Bob theme and I wanted the birthday boys names to POP.

This Coolest Sponge Bob Birthday Cake was a huge success. I received so many compliments and I was told it looked professional. It tasted just as good as it looked and the birthday boys’ felt very special.

Homemade Sponge Bob Birthday Cake

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