Birthday Cake Batter French Buttercream

One confetti cupcake with a swirl of off-white buttercream on top is in focus. Other cupcakes are around it.

This birthday cake batter French buttercream is smooth, silky, and completely irresistible! The base of the recipe is similar to a traditional vanilla French buttercream, but adding two simple ingredients transforms it into a frosting that tastes exactly like cake batter!

I’ve used this buttercream on top of confetti cupcakes, as the filling for macarons, and as a frosting for six inch smash cakes for birthday parties, and it always gets rave reviews.

A large dollop of French buttercream on a spatula.
Look at that luscious dollop!

What is French Buttercream?

Before we get into the ingredients for my birthday cake batter French buttercream, let’s talk about what’s in traditional French buttercream. French buttercream is made from just four ingredients—egg yolks, granulated sugar, water, and unsalted butter. The egg yolks are cooked in a hot sugar syrup and whipped into a fluffy and custardy deliciousness. Extracts are typically added in for flavor, then, butter is added piece by piece until a silky buttercream is formed.

Because of the egg yolks in the French buttercream, this buttercream requires refrigeration. For the absolute best flavor and texture, I recommend letting the buttercream sit out at room temperature for about half an hour before serving. That allows the buttercream to soften up slightly to its full, silky potential.

Ingredients for Birthday Cake Batter French Buttercream

This French buttercream is made with simple ingredients that you probably already have in your pantry and fridge.

What sets this French buttercream apart from other French buttercreams is the salted butter. The salt in the salted butter is balanced with heavy cream and powdered sugar to make a slightly sweet buttercream that tastes exactly like cake batter—without emulsions or artificial ingredients!

  • Egg yolks
  • Granulated sugar
  • Water
  • Salted butter
  • Vanilla extract
  • Powdered sugar
  • Heavy cream
Ingredients for birthday cake batter French buttercream.
All the ingredients you need for this vanilla French buttercream with a little something special!

Quick Tips for Prepping Birthday Cake Batter French Buttercream

French buttercream is more difficult to make than American buttercream, but there’s no reason why you shouldn’t be able to make it if you follow these tips.

Preventing the Egg Yolks from Curdling

The number one problem people have with French buttercream is mixing the hot sugar syrup into the egg yolks quickly enough while the beater is beating fast enough without splattering it everywhere.

It’s easier than it sounds, I promise.

A silver stand mixer is whisking egg yolks.
Whisking the egg yolks together before adding in the sugar syrup is helpful for me.

Start with room temperature yolks. Anything colder has a higher chance of curdling due to the temperature difference between the yolks and the sugar syrup.

Go into it slow, but not too slow. Use level 2 on your KitchenAid or stand mixer—not just the “stir” option. Level 2 combines the syrup with the egg yolks quickly enough to prevent them from curdling, but not so quickly that it begins splattering everywhere.

Start pouring the syrup into the bowl of the stand mixer, making sure that the syrup is running down the side of the bowl before it meets the yolks. That will prevent splatters and helps make sure all the syrup makes its way into the mixture. A small saucepan with a spout really helps this process along.

Once you’ve started, keep pouring the syrup onto that same line of syrup in one slow and steady stream. Go slow enough so that there isn’t a puddle of syrup waiting to be incorporated. That puddle is hot, and it will begin to curdle the yolks if it’s not spread out evenly.

If your yolks end up curdling, don’t worry about it overmuch! You can always push the final product through a fine mesh strainer to get rid of any large lumps.

A whisk with custard filling the bottom in front of a stand mixer.
When your yolk and syrup mixture has cooled down, it will look something like this. Pillowy ribbons of custard that absorb back into the batter.

All about the Butter

A friendly reminder: Use salted butter. Unsalted butter just won’t have the same flavor as salted butter.

When you’re ready to add the salted butter to the French buttercream, the bowl should be almost cool to the touch. If you add in the butter when the custard is warm, the butter will melt. Then, the buttercream won’t whip up properly. Chill the rest of the butter until it is neither cool nor warm before adding in the rest of it.

Along with that, make sure your butter is at room temperature. If your butter is too cold, it will not whip properly. If your butter is too warm, it won’t aerate easily and can turn out a bit dense.

I’ve found that the buttercream comes together a lot better if I introduce the butter in small cubes rather than all at once. You can cut up the butter with a knife or just tear blobs of it off the block—whatever strikes your fancy!

Once all your butter is incorporated, the French buttercream will still be a bit dense (and it won’t have the secret ingredients to transform the saltiness of the butter into birthday cake batter!).

A beater attachment laden with buttercream.
Don’t mind the bit of buttercream I have on the palm of my hand here. It comes with the job.

Adding in the Twist

Finally, add in your vanilla, powdered sugar, and heavy cream. Beat them all together for no less than three minutes, and enjoy your wonderfully fluffy, one-of-a-kind, birthday cake batter French buttercream.

Can I Make this Buttercream Recipe with Unsalted Butter?

You can, but it’s not going to taste the same. I have attempted making this buttercream with unsalted butter, then compensating by adding salt during during the whipping stage. The buttercream turned out a bit grainy, and it contained unpleasant pockets of saltiness. This recipe needs salted butter for the flavor to turn out right.

How Much Buttercream Does this Recipe Make?

This recipe makes about two cups of buttercream. That’s enough to frost 12 cupcakes or simple three-layer 6″ cake with no buttercream decorations, or fill about 90 macarons.

Do I Need to Use a Candy Thermometer?

No, you don’t, but you will need a thermometer of some kind! A candy thermometer is certainly helpful (I love this inexpensive digital one from CDN) but not required. Any instant-read thermometer will do.

A candy thermometer shows the temperature of the sugar syrup in front of a stand mixer.
A candy thermometer (especially one with an alarm!) is helpful, but as long as you have an instant-read thermometer, you’ll be able to make this buttercream.

Recipes that Use Birthday Cake Batter French Buttercream

I have a number of recipes that use this buttercream because it’s always a favorite with my family and friends!

Dish Cleanup: Not too Bad

I rate my recipe cleanups on a scale of 1 to 5. 1 is only a handful of dishes, and 5 is everything including the kitchen sink.

This birthday cake batter French buttercream has a cleanup rating of a 2. There are more dishes involved than an American or Russian buttercream, but the depth of flavor and the creaminess you get from this buttercream is simply too good not to wash a few extra dishes.

A pile of dishes used in making this birthday cake batter French buttercream.
More dishes than an American buttercream recipe, yes, but oh so worth it!

Birthday Cake Batter French Buttercream Recipe

Yield: About 2 cups of frosting, enough for 12 cupcakes or a three-layer 6" cake

Birthday Cake Batter French Buttercream

One confetti cupcake with a swirl of off-white buttercream on top is in focus. Other cupcakes are around it.

Smooth, silky, and completely irresistible, this vanilla French buttercream gets two extra (but simple) ingredients to transform it into a frosting that tastes exactly like cake batter!

Prep Time 10 minutes
Cook Time 10 minutes
Additional Time 10 minutes
Total Time 30 minutes


  • 4 large egg yolks, at room temperature
  • 1/2 cup granulated sugar (100g)
  • 3 Tablespoons water (45 ml)
  • 1 cup salted butter (226g) at room temperature
  • 1 Tablespoon vanilla extract (15 ml)
  • 1/2 cup powdered sugar (50g)
  • 2 Tablespoons heavy cream (30 ml)


  1. Separate the eggs, reserving the yolks. (You can freeze the leftover whites in an air-tight container to make macarons later!)
  2. Place the egg yolks in a bowl of a stand mixer fitted with the whisk attachment and begin beating them on medium low. This is especially important if your yolks are cold, as this recipe works best with room temperature egg yolks. Keep the stand mixer beating the yolks while you make the sugar syrup.
  3. Combine the sugar and water in a small saucepan. Heat over medium heat until the syrup reaches the firm ball stage (245°F/118°C), swirling occasionally to even out any hot spots. I recommend using a candy thermometer, but any digital thermometer will do as long as it's quick or instant read. This should take about 5-10 minutes.
  4. Once the syrup is ready, reduce the speed on the stand mixer to low and slowly and carefully pour the syrup along the inside of the bowl, staying in one spot just outside of reach of the whisk. Try not to get syrup on the tines of the whisk, as the syrup will splatter and cool down before incorporating into the yolks.
  5. Once all the syrup has been poured in, increase the speed on the stand mixer to medium high. After a minute, turn off the mixer and scrape down any sugar syrup on the sides of the bowl with a silicone spatula. Then, continue whisking the yolk mixture on medium high until the bowl no longer feels warm to the touch and the yolk mixture is pale yellow and fluffy.
  6. While waiting, cut up your room temperature salted butter into ½" (12mm) cubes.
  7. When the mixture has cooled, reduce speed to low and begin incorporating the salted butter into the mix, one piece at a time. The buttercream may begin to look like it's curdling or separate at this point—if that happens, switch to a beater attachment. Once all the butter has been added, add the vanilla extract and switch the whisk to a beater attachment (if you haven't already).
  8. Turn off the mixer and add in powdered sugar and heavy cream. Incorporate the additions on low, then beat for two minutes on medium speed to get the buttercream fluffy.
  9. If you want to use the buttercream right away and it's at room temperature or slightly warmer, place the bowl in the fridge for just a few minutes. (This buttercream is smooth and silky, but that comes at a slight cost of melting a little faster than American buttercream.) Do not leave the buttercream in the fridge for more than 20 minutes, as the buttercream will harden too much. If the buttercream hardens in the fridge, wait for it to soften and then beat it again to get a silky smooth consistency.
  10. Place the buttercream into a pastry bag fitted with your preferred tip, or apply directly from the bowl. Enjoy!


French buttercream requires refrigeration because of the egg yolks used to make it. Store your French buttercream or any cakes/cupcakes/macarons/etc filled with this French buttercream in the refrigerator for up to four days for the best flavor.

This recipe makes two cups of buttercream. That's just about right for 12 cupcakes, a simple three-layer 6" cake with no extra decoration, or about 90 macarons.

Nutrition Information:



Serving Size:


Amount Per Serving: Calories: 80Total Fat: 2gSaturated Fat: 1gTrans Fat: 0gUnsaturated Fat: 1gCholesterol: 64mgSodium: 4mgCarbohydrates: 13gFiber: 0gSugar: 13gProtein: 1g

The nutrition facts are estimated and may vary based on specific ingredients used.

Thanks for trying out my birthday cake batter French buttercream recipe! I’d love to see how it turns out: Take a photo and tag me on Instagram @floralapronblog to share with me, or use the hashtag #floralapronbakes.

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Other Recipes You May Enjoy

This buttercream gets used in my confetti cupcakes with French buttercream and my birthday cake macarons because it is just so good!

My strawberry champagne cupcakes are always a hit—moist, complex, and not overly sweet.

My salted caramel sauce is another great salty-sweet dessert combo. Use it to dip apples or mix into hot chocolate for a twist on the classic!

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