This may just be my new favorite frosting recipe!
This silky smooth and lightly sweet frosting is perfect swirled atop cupcakes or as the finish to a layer cake. It would also make the perfect filling for whoopie pies or cookie sandwiches.
The recipe for this heavenly frosting starts just like an American buttercream, with softened butter and confectioners sugar beat until smooth in your mixer. Next comes some marshmallow fluff which gives the frosting more structure. Marshmallow cream is similar to Swiss meringue or a 7-minute frosting; it is a shelf stable meringue. So it is the perfect way to add bulk to a frosting as opposed to adding more powdered sugar.
Finally there is the sour cream, the real star of this simple recipe. When I began making this recipe I would use heavy cream as the sole liquid in this frosting. One day I reached for some sour cream to see how the tang would fit into the overall flavor. Simple perfection! If you don’t have sour cream on hand, plain yogurt or greek yogurt can be substituted. Any of these ingredients will add flavor to this frosting by offsetting the sweetness of the sugar.
If you follow through to my Pumpkin Spice cake recipe you will see how I used this frosting to finish a ‘nearly naked cake.’ This trendy frosting technique is basically a neat crumb coat, with bits of cake showing through a thin layer of frosting. This recipe works will with this technique since the frosting spreads so smoothly and doesn’t drag across the cake.
- 1 pound unsalted butter, softened
- 1 pound confectioners sugar, sifted (about 4 cups)
- 6 ounces marshmallow fluff (about 1 cup)
- 2 ounces full fat sour cream (1/4 cup)
- 1 Tablespoon vanilla extract
- 1 pinch salt
- 3-4 Tablespoons heavy cream
- In the bowl of your stand mixer beat the softened butter for 1-2 minutes until it is creamy
- Add the confectioners sugar and blend on low to combine. Raise the mixer to medium speed and beat for about 1 minute to ensure that there are no lumps of sugar
- Scrape your mixer bowl and beater then add the marshmallow fluff, sour cream, vanilla and salt
- Beat the frosting for about one minute then add half of the cream, blending on low to combine
- Check the frosting consistency, if you'd like it a bit thinner add a touch of the remaining cream
- Give the bowl one final scrape then beat the frosting on medium speed for 4-5 minutes
Excited to try the confetti cake. My daughter always liked them when she was younger.
Hi Sheila! I hope you enjoy it, it’s one of my favorites! Happy Baking! ~Dan
Hey Dan! Thanks for the vanilla frosting. I was looking for a unique frosting for my son’s first birthday cake and I found you and your blog! Tada! Thank you I loved it.
Hi Priya,
It is one of my favorite frostings. Im glad you enjoyed it!
Dan, what brand of vanilla do you prefer?
I like to buy vanilla in bulk- so whatever brand allows me to do that works. Sometimes it is nice to splurge on a gourmet vanilla, but it isn’t necessary.
Hi, I live in the Tropics, in Costa Rica, how can I hold the frosting not to melt.
Hi Enith! I would say to reduce or eliminate the heavy cream to keep the frosting stiffer. You could also replace about 20% of the butter with vegetable shortening to make it hold better. You can certainly frost your cake with this frosting and then chill the cake. This frosting is delicious even when cold!
Happy Baking!
Dan
Hi Dan,
I separated some to add color and write on a cake, it looked broken. Why would that be? Should I let the sour cream come to room temperature before adding? Thank You 
I made this recipe a few weeks ago and loved it.
Katie
Hi Katie- I’m so glad you enjoyed it! I don’t usually color this icing, but I would say it is a temperature issue. Definitely let the sour cream warm up before mixing. If you are coloring a small amount (just enough for writing) you can always warm the colored icing in the microwave for 3-4 seconds and stir to see if that will emulsify everything.
Happy Baking!
Dan
Is this stable enough to pipe flowers and such and have them hold their shape?
HI Hope- I would use the recipe for Dans Favorite Buttercream if you want to pipe flowers. This buttercream is very airy and wont hold flower details as well.
Hey Dan! I would love to try this recipe, but I don’t know what 1 pound 10x confectioner sugar means. How many cups would that be?
The recipe looks great!
HI Logan! One pound of confectioners sugar is about 4 cups. Enjoy the recipe- it is a great one!!!
I just made this because I was looking for that bakery style frosting that is light and not too sweet and this is the perfect recipe! I can’t wait to use it more often! Thank you!
I’m so glad you enjoyed it Zahra!!!