If you've seen those perfectly smooth, colorful or beautifully textured cakes all over social media and wondered how to frost a cake like that, you've come to the right place! This beginner's post covers all the cake frosting basics: Essential equipment, types of frosting, estimating how much frosting you'll need and, ultimately, how to frost the perfect cake.
Disclaimer: Please note that some of the links below are affiliate links and I will earn a commission if you purchase through those links. I use all of the products included in this post and recommend them because they are products I personally love and trust.
If you're new to the wonderful world of cake-making and decorating, this post is for you! While frosting a cake may sound simple, and it absolutely can be, you don't want to be elbows-deep in a bowl of frosting when the questions hit you.
"Did I make enough frosting? And how much frosting does a cake take??"
"Should I have bought an offset spatula?"
"How does everyone get that perfectly smooth finish anyway?"
"What am I even doing with my life??"
Ok, maybe I can't help you with the latter, but keep reading for the answers to the first three questions and more.
While there's a lot you can do without fancy cake-decorating equipment, here are a few things I simply wouldn't want to decorate without.
- A metal bench scraper (affiliate link): This is perfect tool for getting a perfectly smooth finish on your cakes and the all stainless steel finish washes up wonderfully. It's also great for making bread, pastries and pasta, among other things.
- A high quality cake turntable (affiliate link): Do yourself a favor and skip the cheap plastic ones - They tend to hold onto the grease from butter and rarely turn in one smooth motion, making getting that smooth finish near impossible. Ateco's cast iron cake turntable (affiliate link) is the one I've used for almost a decade and it's well worth its price.
- Offset spatulas in different sizes (affiliate link): Offset spatulas are great for frosting all sorts of baked goods and having a few different sizes to choose from means you always have the right spatula for the job.
- Gel food coloring (affiliate link): The Americolor food coloring I've linked to the left is, hands down, my favorite food coloring. Unlike the kind you find at the grocery store, this food coloring is highly pigmented, doesn't mess with the consistency of your frosting and comes in easy-to-use squeeze bottles.
- Bowls in various sizes that are glass, ceramic or metal. Plastic bowls are difficult to clean thoroughly enough to remove all of the grease, and if you're making a meringue-based buttercream (more on that below) the grease can keep your meringue from reaching stiff peaks.
- A stand or handheld mixer: If it's within your budget, I highly recommend a stand mixer as it allows you to work on other parts of cake prep while the frosting whips. I personally use and love my 5 quart KitchenAid (affiliate link).
- A good serrated knife: Having a long, sharp serrated knife makes cutting layers of cake a breeze.
If you have the budget, here are a few non-essential but super helpful items I recommend to make frosting cakes a breeze:
- Piping bags: If you plan on piping onto your cake, it can be helpful to have disposable piping bags. I have both a canvas bag and disposable ones, but once you clip the tip on the canvas one, that's the size you're stuck with.
- Piping tips: If you're just starting out, it can help to have some basic piping tip options for creating borders, swirls and other embellishments. I've linked my favorite (and also first) set of tips.
- Patterned cake scraper (affiliate link): If you're looking for an easy way to add texture or alternating frosting stripes to your cake, having a patterned cake scraper makes for quick work.
The best frostings for layer cakes
Although all frostings are delicious, they're not all ideal for frosting layer cakes. Layer cakes are often heavy (for example, the three layers of cake used in my 6" fudge sundae cake weigh about one pound each) and, as such, need a firm frosting to support and hold the layers in place.
With that in mind, your best options are a buttercream or a thick ganache (not to be confused with a ganache drip). Here are my favorites:
- American buttercream: This frosting is made with butter, powdered sugar and flavoring. It's very easy to make, forms a nice crust and is generally sweeter than the buttercreams that are to follow.
- Italian meringue buttercream: When I have the time, this is my go-to frosting recipe. Italian meringue buttercream combines a sugar syrup, egg whites, butter and flavoring. It's less sweet than its American counterpart and forms a nice crust but takes a little more time to make on account of needing to bring the hot sugar syrup down to room temperature.
- Swiss meringue buttercream: Like an Italian meringue buttercream, swiss meringue uses egg whites. But unlike the Italian buttercream, the Swiss version combines and cooks the egg whites with the sugar, beats them to stiff peaks and then calls for adding the butter. This buttercream is also less sweet than an American buttercream, stable, forms a nice crust and takes a similar amount of time to make as the Italian meringue buttercream.
- Ganache: At a 2:1 ratio of dark chocolate to cream, ganache makes an excellent frosting that can be whipped or used straight. It has a rich, chocolatey flavor, forms a soft shell kind of finish and is very easy to make (although will require some cooling time).
If your cake is a relatively low or light cake with few layers, you might be able to get away with other frostings.
And if you're ever in doubt, you can always fill your layer cakes with one kind of frosting and coat the outside with a less stable frosting for a different flavor.
A note on adding soft fillings: If you'd like to add a soft filling like a fruit compote, pastry cream, caramel or so on, you can do this by adding a ring of one of the frostings above around the edge of the layer to hold the filling in and provide stability to the stacked layers.
Once you've picked out a frosting to use, the next step is to estimate how much you'll need. This will depend not only on the size of your cake, but also how many layers you have, how thick those layers are and how much frosting you want between each layer and around the outside.
So how do you know how much frosting to make? Let me do the math so you don't have to!
Below you'll find a helpful chart with estimates on approximately how much frosting you'll want to make. If you're looking for estimations for cupcakes, you can find those here.
An important note: In order to make these calculations, I had to make a few assumptions and I want to be up front about what those are so you know if you need to prepare more or less frosting.
These estimates assume your cake layers are 1 ½" tall and that you're using ⅓" frosting between layers and around the outside.
Adding buttercream decorations
If you plan on adding a buttercream border or swirls to the top, you'll want to add 1-2 cups of frosting onto your estimate, and if you plan on doing a buttercream intensive design, you'll want to add another 2-3 cups just to be on the safe side. It's always easier to prepare more than you think you'll need, and any leftover frosting can be frozen in an air tight container for up to three months.
If you're interested in learning more about how I came up with these estimates so you can do your own calculations, here's how I did the math:
For the round cakes: I used the formula for the volume of a cylinder (π x radius2 x height) multiplied by the number of layers to calculate the volume of frosting between the layers and for the top of the cake. I then calculated the volume of frosting for the outside of the cake by "unwrapping" it into a rectangular prism (width x length (which I calculated by finding the circumference of cake, using π x radius2) x height). I added these numbers together and then divided by 14.4 which is how many cubic inches are in a cup.
That means the full equation for calculating the amount of frosting to frost a round layer cake is ((π x radius2 x height) x number of layers) + (width x length (π x radius2) x height) / 14.4
For the square cakes: I used the formula for the volume of a rectangular prism (width x length x height) and multiplied it by the number of layers to estimate the amount of frosting needed between the layers and for the top of the cake. I then used that same formula (width x length x height) and multiplied the length by four to get the volume of frosting around the outside of the cake.
This means the full equation for estimating the amount of frosting for square layer cakes is (length x width x height x number of layers) + (length x 4 x width x height of cake).
How to frost a cake
First, level (torte) your cake layers.
A beautifully frosted cake starts with good bones (layers). It's natural for cakes to rise a little unevenly, with a domed top or even some cracks, so if your cakes aren't perfectly level that's ok.
The simplest way to level a cake is to start by chilling it. This will make it easier to handle and cut. I like to wrap mine in plastic wrap and chill them in the refrigerator for at least an hour.
Once the cake is cold, use a serrated knife (a bread knife works well) to level the top. To ensure the cut is level, use a sawing motion while gently turning the cake until you come all the way around. Repeat with each layer.
Remember, you can always cut off more so it's best to err on the side of cutting less off at a time.
Second, frost the layers.
with your first layer of cake on a plate or cake board, spread ⅓" of frosting across the top using an offset spatula. Gently press the next layer of cake onto the top of the first and repeat.
If you plan on adding a soft filling between the layers, spread a very thin layer of frosting over the cake to seal in the crumbs. Pipe a ring of frosting around the edge and fill the center with the filling. Cover with the next layer and repeat.
A note about plate selection: It's best to choose a completely flat, rimless plate (or use a cake board) for frosting cakes. This will keep your cake from bowing in the middle and will allow you to use any and all tools without a rim/lip getting in the way.
Third, crumb coat the cake.
Crumbing coating (sometimes already referred to as "dirty icing") is spreading a thin layer of frosting over the outside of the cake to lock in the crumbs. This is particularly important if you're working with a dark cake and a light frosting.
To do this, pick up a little bit of frosting on your offset spatula and spread it over the top of the cake. Work your way down the sides adding more frosting as you need to cover the entire cake in a thin layer. You should still be able to see the cake through this layer of frosting.
Refrigerate until the frosting develops a crust (about 20-30 minutes).
A note on keeping crumbs out of your frosting bowl: As you work on this step of the cake frosting process, it's a good idea to wipe any excess frosting off of your spatula onto the side of a separate bowl. It kind of defeats the purpose of locking in those crumbs if you're putting them right back into your bowl of frosting.
Finally, cover with the remaining frosting.
No matter how I'm decorating my cake, I like to start by frosting the top and then working my way down the sides.
Picking up frosting with your offset spatula, spread it generously over the top and sides of the cake.
It's ok if it looks a little messy or if it seems like a lot; We'll clean it up and remove the excess in the next step.
How to smoothly frost a cake
Getting that perfect smooth frosting finish comes down to two things: Choosing the right frosting and your technique.
If you read the previous section on frostings and choose one of the recommended ones, you should be off to a good start. Both buttercream and ganache frostings develop a thin crust, which makes creating a smooth finish a little easier.
The other thing you'll want from your frosting is as few air bubbles as possible. One easy way to achieve this: Beat it on the lowest setting for 3-5 minutes. You can also use a silicone/rubber spatula to press the frosting against the sides of the bowl to work out the bubbles by hand.
As for the technique, you'll need a metal bench scraper and a cake turntable.
Hold the bench scraper at a 90-degree angle against the frosted cake and turn the cake turntable.
Once you've gotten the frosting mostly smooth, rinse the bench scraper off in your sink using the hottest water your faucet will produce. Take the now hot bench scraper and gently run it around the outside of the cake.
The heat from the bench scraper will ever-so-slightly melt the outermost layer of the frosting, creating that beautiful smooth finish.
- Chill your cake: A cool cake is easier to cut and handle, so chilling your cake for a short while before frosting it will make the whole process a lot easier.
- Fixing a "broken" meringue-based buttercream: Sometimes you'll find that your buttercream looks "broken" or curdled. There are usually two culprits: Either it hasn't been beaten long enough or the frosting is too warm (either from the butter being too warm or being added to the meringue too early). If continuing to beat it doesn't work, try putting it in the refrigerator for 30 minutes to cool, then continue beating.
- Air bubble-free frosting: If your frosting has a lot of air bubbles in it, beat it on the lowest speed for 3-5 minutes.
- Crumb coating: Crumb coating means spreading a thin layer of frosting over the sides and top of the cake and then chilling it. This locks in all of the crumbs so they don't get into the outer layers of frosting. This is a particularly important step if you're working with a dark cake and a light frosting.
- Storing a cut cake: Once your cake is cut, you'll want to protect the exposed part. The easiest way to do this is to place a piece of plastic wrap directly onto the exposed cake.
Frequently asked questions
Particularly tender cakes can be prone to tearing, particularly if you're using a thick frosting. If this is a concern, wrap the cake in plastic wrap and refrigerate it until thoroughly chilled or use a softer frosting.
Yes! While it's not required, it's highly recommended as a well chilled cake is easier to cut, frost and handle.
Absolutely! For a smooth finish, simply load up a piping bag with a large, round tip and pipe the frosting directly onto the sides and top. Use an offset spatula or bench scraper to smooth it. You can also create lots of texture by using different tips to pipe the frosting onto the cake.
For the most part, yes. Most store-bought frostings won't crust the same way a homemade buttercream will, which can create issues when it comes to getting a really smooth finish.
Frosted cakes can be stored in the refrigerator for up to 3 days prior to serving.
Yes, you can frost a frozen cake but you don't want to level (torte) it while it's frozen, otherwise the cake can come off in chunks.
Yes! Cakes frosted with whipped cream or Cool Whip should be light (like a sponge cake) and have relatively few layers, like this marzipan cake. Cakes filled/frosted with whipped cream should not be stacked in tiers.