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A Smash Cake is the adorable little cake your baby gets to dig into and demolish on their first birthday, and this easy ombre box-mix version looks bakery-fancy with almost zero skill required. I made my first one for Lizzie’s big day and ugly-cried the entire time she smashed it to bits. If you love a fun, festive bake, try our strawberry earthquake cake next.
With a boxed cake mix and canned frosting, you can pull off a showstopping ombre smash cake even if you have never decorated a cake in your life.
Smash Cake Quick Look
- 🕒 Prep Time: 45 minutes
- 🌡️ Cook Time: 29 minutes
- ⏳ Total Time: 2 hours
- 🍽️ Serving: 28 servings
- ⚡ Calories: 210kcal
- 🌶️ Flavor Profile: Sweet vanilla rainbow chip cake with fluffy ombre frosting
- ✋ Difficulty: Beginner friendly, a fun box-mix project like our strawberry earthquake cake
Quick Answer
Bake two small cake layers from a boxed mix and let them cool completely. Level and stack them with a thin crumb coat of frosting. Tint vanilla frosting into two shades, then frost the bottom third with the darkest shade, the middle with a medium shade, and the top with white. Smooth and blend the bands into a seamless ombre, then decorate the top with sprinkles.
Jump to:
Why This Recipe Works
Click to see the technique science
- A boxed mix keeps it foolproof. Starting with cake mix and canned frosting means consistent results with none of the from-scratch guesswork.
- The crumb coat locks in crumbs. A thin first layer of frosting traps loose crumbs so your final ombre coat stays clean and smooth.
- Tinting one jar in shades. Splitting a single jar of frosting into graduated shades gives you a perfect ombre without buying multiple colors.
- Frosting in bands. Applying dark, medium, and white in horizontal bands lets you blend them into a seamless gradient as you smooth.
- Smoothing from the bottom up. Light pressure with an offset spatula, working bottom to top, melds the colors and erases the seams.
Why You’ll Love This Recipe
- It looks like it came from a fancy bakery but uses a boxed mix and canned frosting.
- It is perfect for a first birthday smash cake plus a matching cake for the party guests.
- The ombre technique works with any color, just like decorating our lemon cake with lemon buttercream.
Key Ingredients
Just a few simple store-bought staples come together for this bakery-worthy smash cake.
- Boxed Cake Mix: Party Rainbow Chip is fun and festive, but any flavor works. You will need two boxes for all four layers.
- Vanilla Frosting: Canned frosting makes the ombre effect easy. Save one jar for tinting into shades.
- Butter and Eggs: They enrich the boxed batter for a moister, more homemade tasting cake.
- Gel Food Coloring: Gel gives you vivid color without thinning the frosting. Pick any shade you love.
- Sprinkles: Optional, but perfect for a number topper or a festive finish.
See recipe card for exact quantities.
Variations and Substitutions
Make this smash cake your own with these easy ideas.
- Any color ombre: Pink, purple, green, or rainbow all work with the same tinting method.
- Change the flavor: Chocolate, funfetti, strawberry, or lemon cake mix all work beautifully.
- Single smash cake only: Make just the 6-inch layers if you only need the baby cake.
- Add a topper: Use a sprinkle number, a candle, or a small cake topper.
- Homemade frosting: Swap canned for a batch of our cream cheese frosting.
How to Make Smash Cake
- Preheat the oven to 350 degrees. Mix the cake batter with water, melted butter, and eggs, then divide between two 9-inch and two 6-inch pans. Bake, then cool completely.
- Level off any domed tops so the cakes are flat. Stack the layers with a thin layer of frosting between them, then apply a thin crumb coat over the whole cake.
- Take one jar of vanilla frosting and divide it evenly between two bowls.
- Tint the first bowl to your desired shade, then tint the second bowl with about half as much color so you have one darker and one lighter shade.
- Frost the bottom third of the cake with the darkest shade, the middle third with the medium shade, and the top third plus the top with plain white frosting.
- Using an offset spatula, start at the bottom and smooth the frosting all the way around the cake with light pressure.
- Continue smoothing up the sides, blending the bands together into a seamless ombre gradient. Scrape excess frosting into a clean bowl as you go.
- Decorate the top with a sprinkle number in place of a candle, then repeat the frosting and smoothing with the second cake.
Recipe Tips & Tricks
- Cool the cakes completely. Frosting a warm cake melts the frosting and pulls up crumbs. Chill the layers if you are short on time.
- Crumb coat first. That thin first layer is the secret to a clean, smooth ombre finish.
- Use gel food coloring. It gives vivid color without thinning the frosting like liquid coloring does.
- Keep a clean bowl handy. Scrape excess colored frosting off your spatula so you do not muddy the white top.
- Chill between coats. A quick 15-minute chill firms the crumb coat before the final ombre layer.
- Embrace imperfection. A little texture and waviness gives the ombre a soft, dreamy look.
Serving Ideas and Suggestions
A smash cake is the star of any first birthday, set in front of the birthday baby for that messy, joyful photo op. Make the matching 9-inch cake for the guests so everyone gets a slice while baby demolishes their own.
Serve it alongside other party treats like a tray of angel food cupcakes or a batch of banana cupcakes for a full dessert table.
Slice the larger cake into thin pieces since boxed mix makes a generous amount. Leftovers keep covered at room temperature for a day or in the fridge for several days.
Smash Cake FAQs
A smash cake is typically a small 4-inch or 6-inch round cake sized just right for a one-year-old to dig into. This recipe makes 6-inch baby cakes plus larger 9-inch cakes for the party guests.
Yes, a thin crumb coat is the key to a smooth smash cake. It traps loose crumbs so the final ombre frosting layer goes on clean and looks polished.
Yes. Bake and freeze the cooled cake layers up to a month ahead, then thaw and decorate the day before the party. Store the finished smash cake covered in the fridge.
Canned vanilla frosting makes the ombre effect easy, but homemade buttercream or cream cheese frosting also works. Just make sure it is soft enough to spread and smooth.
This smash cake uses standard cake ingredients, so check for any allergies first. For a less sugary option, you can make a reduced-sugar or whipped-cream version for the baby cake.
Tint one jar of frosting into two shades, frost the cake in horizontal bands from dark at the bottom to white on top, then smooth with an offset spatula to blend the colors into a seamless ombre.
Planning a party? Pair this smash cake with our rich chocolate caramel cake for the grown-ups.
How To Make a Smash Cake (Box Mix Tutorial)
Ingredients
- 2 boxes Party Rainbow Chip cake mix or cake flavor of your choice
- 2 cups water
- 1 cup butter melted
- 6 large eggs
- 3 – 16 ounce cans Vanilla Frosting
- blue gel food coloring or color of your choice
- sprinkles optional
Instructions
- Preheat the oven to 350°F. Spray 2 9-inch round cake pans and 2 6-inch round cake pans with baking spray and set aside.
- Add the two cake mixes with the water, butter (melt butter in the microwave and let cool on the counter for about 10 minutes before adding to batter), and eggs.2 boxes Party Rainbow Chip cake mix, 2 cups water, 1 cup butter, 6 large eggs
- Mix with a hand mixer on medium speed for 30 seconds until moistened. Mix on high speed for two minutes.
- Spread 2 3/4 cups batter in each 9-inch round pan. Spread 1 3/4 cups batter in each 6-inch round pan. Bake 9-inch pans for 24 to 29 minutes and 6-inch pans for 22 to 27 minutes, or until a toothpick inserted in the center comes out clean.
- Let cool for 10 minutes in the pan, then flip them out of the pan and let cool completely on a wired rack before frosting.
- (You will repeat the next steps for the two different cake sizes) Carefully cut off any doming on the cakes so there is a flat surface.
- Place the first cake bottom side down onto your serving platter. Top with a thin layer of white frosting.3 – 16 ounce cans Vanilla Frosting
- Place the second layer on top of the first, bottom side up, so it is nice and flat. Add an extremely thin layer of frosting over the entire cake using a flexible spatula—place in the fridge for at least 10 minutes to set.
- Repeat with the other cake layers.
- Taking one jar of the vanilla frosting, place 1/2 of the frosting in a bowl and the other 1/2 in another bowl.blue gel food coloring
- Add food coloring to the first bowl until you reach your desired shade. To the second bowl, add about half less of the same food coloring so there is one darker and one lighter.
- Using the darker color, frost the bottom 1/3 of the cake with an off-set spatula or flexible spatula.
- With the medium shade, frost the middle third of the cake.
- Add the plain vanilla frosting to the top 1/3 of the cake and a thicker layer on top. Don’t worry if it looks messy at this point; so did mine!
- Using an off-set or flexible spatula, you are going to smooth down the sides and blend the colors. Have a clean bowl nearby to scrap off any excess frosting.
- Starting at the bottom, apply light pressure enough to smooth the frosting and go around the entire bottom of the cake. Once you go around the whole cake, move the spatula up the side just above the smooth spot and go around the cake again until you have done the entire cake. Your ombre frosting is done!
- Repeat with the second cake.
- I also put the “1″ as decoration on the top in place of a candle. I just drew out a stencil of the number how I wanted it to look. Gently pressed it to the top of the cake and filled in the stencil with sprinkles.sprinkles
Notes
- Use a serrated knife to level the cake layers for an even look.
- Chill the cake layers before assembling to make handling easier.
- Apply a crumb coat of frosting and chill before adding the final coat for a cleaner look.
- Practice the frosting technique on the side of a bowl or cup before moving on to the cake.
- Let the cake come to room temperature before serving to ensure the best flavor and texture.
- Have fun with it! This cake is all about making memories, so don’t stress over perfection.
Nutrition
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Totally adorable! Thanks for linking up with What’s Cookin’ Wednesday!
Awesome! I love using cake mixes: they taste great, and it makes everything so much faster 🙂 Beautiful ombre too. Pinned! I would love for you to share this post at my Create & Share Link Party tonight (7:00 PM MST)! Hope to see you there 🙂 http://designsbymissmandee.blogspot.com/