Healthier Strawberry Banana Smash Cake : Easy Baby Birthday Cake Recipe

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If you are looking for a baby-friendly first birthday cake that is as beautiful as it is wholesome, this Healthier Strawberry and Banana Smash Cake is exactly what you need. Built on a naturally sweetened banana oat cake base and crowned with a silky strawberry Swiss meringue buttercream, this smash cake skips the refined sugar without skipping the celebration. Think of it as a nod to the vintage Strawberry Shortcake aesthetic charming, colorful, and full of love for your little one’s big milestone.

Why You Will Love This Recipe

• No refined sugar sweetened entirely by ripe bananas
• Made with whole wheat Einkorn flour and steel cut oats for added nutrition
• The strawberry buttercream is naturally colored with dehydrated strawberry powder
• Perfect for a Strawberry Shortcake birthday theme
• Can be made ahead and frozen for stress-free party prep
• Baby-safe and toddler-approved

Ingredients You Will Need

Healthy Banana Cake for Baby

3:2:1 Ratio Swiss Meringue Buttercream

Kitchen Equipment You Will Need

• Oven for baking the banana cake layers
• Electric mixer (stand mixer) essential for whipping the Swiss meringue buttercream to stiff peaks
• Pots for creating a double boiler to heat the egg whites and sugar
• Mixing bowls including a heatproof stainless steel bowl for the meringue
• Kitchen utensils spatulas, whisk, and angled spatula for assembly
• Measuring cups and spoons set for accurate ingredient measurements
• Kitchen scale this recipe uses grams for precision
• Baking sheets useful for placing cake pans during baking

How to Make the Banana Cake Layers

1. Pre-heat your oven to 375F.
2. Melt butter in the microwave on high for 15 to 25 seconds until fully melted. Skip this step if using avocado oil.
3. In a small mixing bowl, combine the whole wheat Einkorn flour, steel cut oats, baking powder, and ground cinnamon.
4. In a large mixing bowl, mash the ripe bananas with a spatula or potato masher using your kitchen utensils. Add eggs and stir until fully incorporated.
5. Add the melted butter or avocado oil and stir to combine.
6. Add the dry ingredients to the wet mixture and gently stir until just incorporated. Do not overmix.
7. Pour the batter into two 4.5-inch cake pans that have been buttered or lined with parchment paper. Place them on a baking sheet before transferring to the oven.
8. Bake until a toothpick inserted in the center comes out clean.
9. While still hot, use a long serrated knife to level off the domed top of each cake layer.
10. Transfer to a cooling rack and allow to cool completely before frosting. You may freeze the layers at this point if making in advance.

How to Make the Strawberry Swiss Meringue Buttercream

1. Set your butter out ahead of time to reach room temperature.
2. Bring a small pot of water to a boil to create a double boiler.
3. Place the egg whites and granulated sugar into a heatproof mixing bowl stainless steel is ideal. Set it over the boiling water and gently whisk the mixture, paying close attention as it heats up to avoid cooking the eggs.
4. Continue whisking until the mixture reaches 160F. Use a kitchen thermometer to verify the temperature.
5. Pour the heated mixture into the bowl of your electric stand mixer fitted with the balloon whisk attachment.
6. Whip on low speed first, then gradually increase to medium speed.
7. Whip until stiff peaks form and the bottom of the bowl feels cool to the touch. Stop the mixer.
8. Switch to the paddle attachment on your electric mixer.
9. Add room-temperature butter a little at a time while beating on medium speed. The mixture may look curdled or broken for a moment this is completely normal. Keep mixing and it will come back together into a smooth, silky buttercream.
10. Add the dehydrated strawberry powder and whip until fully incorporated.
11. Using a flexible spatula from your kitchen utensils set, fold out any excess air from the frosting until it is smooth enough to pipe or spread. Use immediately or freeze.

How to Assemble the Smash Cake

1. Apply a small amount of buttercream to the cake stand to act as glue, then place the first cake layer on top.
2. Apply a generous layer of strawberry buttercream on top of the first layer using an angled spatula from your kitchen utensils collection.
3. Gently place the second cake layer on top.
4. In a separate small mixing bowl, place a small amount of buttercream and use the angled spatula to apply a thin crumb coat over the entire cake. This seals the crumbs and creates a clean base for decoration.
5. Refrigerate the crumb-coated cake to let it set.
6. Transfer the remaining frosting to a piping bag fitted with a 4B Open Star piping tip.
7. Pipe buttercream stars in a horizontal pattern around and on top of the cake.
8. Add any desired cake toppers and serve immediately, or store in the refrigerator for up to 3 days.

Pro Tips for the Best Smash Cake

• Use very ripe bananas: The riper the bananas, the sweeter and more flavorful your cake will be no added sugar needed.
• Weigh your ingredients: This recipe is gram-based for accuracy. A reliable kitchen scale makes all the difference.
• Do not rush the buttercream: If your Swiss meringue buttercream looks broken or soupy, keep mixing with your stand mixer. It will come together.
• Make it ahead: Both the cake layers and the frosting can be frozen separately and assembled the day before the party.
• Level your cake layers: Using a serrated knife while the cake is still warm makes leveling much easier and gives you a professional-looking result.
• Room-temperature butter matters: Cold butter will break the buttercream emulsion. Let your butter fully come to room temperature before adding it to the meringue.

Frequently Asked Questions

Can I make this healthier strawberry banana smash cake in advance?

Yes! Both the banana cake layers and the Swiss meringue buttercream can be made ahead of time and frozen separately. Thaw overnight in the refrigerator before assembling the cake.

Is this smash cake safe for babies under 1 year old?

This recipe contains no refined sugar and uses whole food ingredients, making it a much gentler option than traditional cakes. However, always consult with your pediatrician before introducing new foods, especially eggs and dairy.

Can I substitute the Einkorn flour in this healthier strawberry banana smash cake?

You can use regular whole wheat flour as a substitute for Einkorn flour. The texture may vary slightly, but the result will still be a delicious, wholesome cake your little one will enjoy.

Why does my Swiss meringue buttercream look curdled?

This is completely normal and happens when the butter is added to meringue that is still slightly warm. Keep mixing at medium speed with the paddle attachment on your electric mixer and it will smooth out beautifully.

Can I use fresh strawberries instead of dehydrated strawberry powder?

Dehydrated strawberry powder is strongly recommended for this buttercream because it adds concentrated strawberry flavor without adding extra moisture, which could cause the buttercream to break. Fresh strawberry puree can work but requires more careful technique.

What piping tip should I use for this smash cake?

A 4B Open Star piping tip is recommended for creating those beautiful rosette-style stars that give this cake its elegant, Strawberry Shortcake aesthetic finish.

Equipment List

• Oven
• Electric mixer (stand mixer)
• Pots
• Mixing bowls
• Kitchen utensils
• Measuring cups and spoons set
• Kitchen scale
• Baking sheets

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Healthier Strawberry Banana Smash Cake : Easy Baby Birthday Cake Recipe

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A healthier smash cake for baby’s first birthday made with a naturally sweetened banana oat cake base and silky strawberry Swiss meringue buttercream. No refined sugar, wholesome ingredients, and beautiful Strawberry Shortcake aesthetic.

• Author: Alice
• Prep Time: 30 minutes
• Cook Time: 25 minutes
• Total Time: 55 minutes
• Yield: 1 two-layer 4.5-inch smash cake (serves 4-6)
• Category: Dessert, Baby Cake
• Method: Baking
• Cuisine: American
• Diet: Vegetarian

Ingredients

Scale 1x2x3x

100g whole wheat Einkorn flour

100g quick cooking steel cut oats

1/2 tsp baking powder

1/2 tsp ground cinnamon

460g ripened bananas (approx. 4 bananas)

4 large eggs

40g melted butter (OR 28g avocado oil)

98g egg whites

196g granulated sugar

294g butter at room temperature

1 tbsp dehydrated strawberry powder

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Instructions

1. Pre-heat oven to 375F.

2. Melt butter in microwave 15-25 seconds until fully melted. Skip if using avocado oil.

3. In a small bowl mix flour, oats, baking powder, and cinnamon.

4. In a large bowl mash bananas, add eggs and stir until incorporated.

5. Add melted butter or avocado oil and stir.

6. Add dry ingredients and gently stir until just incorporated.

7. Pour into two 4.5-inch buttered or parchment-lined cake pans.

8. Bake until a toothpick comes out clean.

9. Level the warm cakes with a serrated knife. Cool on a rack.

10. For buttercream: whisk egg whites and sugar over a double boiler until 160F.

11. Whip meringue in stand mixer until stiff and cool.

12. Switch to paddle attachment, add butter gradually until smooth and silky.

13. Add dehydrated strawberry powder and whip until incorporated.

14. Fold out air with a spatula.

15. Assemble: apply crumb coat, refrigerate, then pipe stars with a 4B tip.

16. Serve immediately or refrigerate up to 3 days.

Notes

Use very ripe bananas for maximum natural sweetness.

Buttercream may look curdled when adding butter — keep mixing, it will come together.

Both cake layers and frosting can be made ahead and frozen.

Always use a kitchen scale for gram-based accuracy.