How to frost a smooth cake with buttercream

Today’s tutorial is all about how to frost a smooth cake. Getting that nice, smooth finish when icing a cake can take some practice, but I have been asked so many times about how I get my icing so smooth, I’ve finally put together some instructions that I hope will be helpful. Just remember you have to be patient. My first cake did not look like my current cakes. It took practice – and the right tools.

Update 8/5/16: There’s now a video showing the technique towards the end of this post.

Tutorial - How to frost a perfectly smooth cake with buttercream icing! Images and animated gifs with detailed instructions!

So to start, let’s talk about the tools you’ll need:

Icing tips (this one – Wilton #789 – for icing the sides and this one – Ateco 844 – for piping the border)
Icing bags
Turntable (I use this one)
Icing smoother (I 100% recommend this one over any other)
9 inch offset spatula (I use this one)
Fondant smoother (I use this one)
Viva paper towels (Viva brand specifically)

Let’s talk about that icing smoother for a second. I linked to it above, but it’s an Ateco smoother that costs less than $5. It is the best money I have ever spent on a tool. I used to use another one, but it was big and clunky and I had no idea how much it hindered my ability to get a nice, smooth cake until I tried this one. It’s lightweight, small and easy to use.

In addition to those tools, you’ll obviously need a cake and some icing. I used regular American Buttercream (recipe here). For my cakes that are about this size, I go through about 2 1/2 recipes worth.

For this tutorial, I started with a cake that was already crumb coated and had a layer of icing on the top of the cake. It’s important to already have the top layer on the cake and get it as smooth as you can with your offset spatula. It’ll get further smoothed later, but it’s best to have it smooth now too.

The crumb coat isn’t entirely necessary for every cake. Typically chocolate cakes are more likely to need them, since they tend to have more crumbs. But because of the way I add my icing, it’s not always necessary. I use an icing tip and bag, which reduces crumbs mixing into the icing.

Tutorial - How to frost a perfectly smooth cake with buttercream icing! Images and animated gifs with detailed instructions!

So to get started from here, you’ll want your icing bag fitted with the Wilton #789 icing tip and filled with icing. Starting from the bottom of the cake, pipe icing around the edge, trying to keep even pressure on the bag so that the layer of icing is even.

Tutorial - How to frost a perfectly smooth cake with buttercream icing! Images and animated gifs with detailed instructions!

You’ll have multiple layers of piped icing, depending on the height of your cake. The top layer needs to stick above the top edge of the cake. This will be important later for smoothing the top edges/corners of the cake.

Tutorial - How to frost a perfectly smooth cake with buttercream icing! Images and animated gifs with detailed instructions! Tutorial - How to frost a perfectly smooth cake with buttercream icing! Images and animated gifs with detailed instructions!

When you are done applying the icing to the sides of the cake, it’s time to smooth it. This is where the icing smoother comes in. Place it against the side of the cake. You want to hold it straight up and down, as straight as possible. Hold your icing smoother in the same place and use your other hand to turn the turntable. Continue to turn the turntable, scraping the icing off of the smoother occasionally so that there isn’t too much buildup. I clean off my smoother regularly and when I scrape the excess icing off of it, I usually also wipe it with a paper towel, so that there isn’t anything left on there that will mess up the icing once I place it back on the side of the cake.

Tutorial - How to frost a perfectly smooth cake with buttercream icing! Images and animated gifs with detailed instructions!

Here is an image showing the angle at which I hold the smoother. I really believe the angle makes a big difference in the way the icing smooths. Do not hold it at 90 degrees. The tighter the angle (like shown), the better the excess icing pulls around the cake and fills in gaps.

Tutorial - How to frost a perfectly smooth cake with buttercream icing! Images and animated gifs with detailed instructions!

After doing a few turns of the turntable, you’ll notice some gaps that are deeper and should probably be filled in. I usually notice it at the “seems” where the three layers of icing were piped on. At this point, use your offset spatula to add some icing to the gaps. You’ll want to have a little excess icing, rather than too little.

Tutorial - How to frost a perfectly smooth cake with buttercream icing! Images and animated gifs with detailed instructions! Tutorial - How to frost a perfectly smooth cake with buttercream icing! Images and animated gifs with detailed instructions!

Begin smoothing the sides again, pulling the excess icing around the cake to fill in gaps, then wiping off the icing smoother as needed.

Tutorial - How to frost a perfectly smooth cake with buttercream icing! Images and animated gifs with detailed instructions! How to frost a perfectly smooth cake with buttercream icing! Images and animated gifs with detailed instructions!

Continue working around the outside of the cake, pulling the icing, then scraping it off of the icing smoother. You can fill in more gaps if needed, just keep working the sides until you are happy with it.

Tutorial - How to frost a perfectly smooth cake with buttercream icing! Images and animated gifs with detailed instructions!

You should end up with a cake that looks like this. The sides are mostly smooth and the excess icing from the top is still sticking up above the cake. In some places you may have tiny little holes from the air in the icing. The angle that you hold the icing smoother can make a difference in how many of those you end up with. Again, tighter angle is better. Also, some of those will fill in as we smooth the sides again later with a paper towel.

Tutorial - How to frost a perfectly smooth cake with buttercream icing! Images and animated gifs with detailed instructions!

Next is always the scariest part! The top edges/corners. It was even harder to do these while taking photos. 🙂 The whole icing process took longer than normal, so my icing started to crust a bit and so it’s a little drier in the photos than yours should be at this point. You want to work as quickly as you can. If the icing starts to crust, it’s harder to work with.

To do the edges, you can use the icing smoother or the offset spatula. I use either, depending on my mood, though often I do feel like the offset spatula gives me more control. Pull the icing in towards the middle of the cake, making the corner level with the top of the cake. The spatula should be at about a 45 degree angle. The excess icing should help fill in any uneven-ness on those top corners as you pull it in.

Tutorial - How to frost a perfectly smooth cake with buttercream icing! Images and animated gifs with detailed instructions!
Tutorial - How to frost a perfectly smooth cake with buttercream icing! Images and animated gifs with detailed instructions!

Go all the way around the cake, until it looks like the one below. Again, my icing is a bit drier than yours should be. Hopefully, your cake top is a bit smoother.

Tutorial - How to frost a perfectly smooth cake with buttercream icing! Images and animated gifs with detailed instructions!

Use your offset spatula to continue to work the icing on the top of the cake and smooth the top edges. Do not mess with the sides or side part of the corners yet. Just try to get the top as smooth as you can, the sides should already be smooth.

Tutorial - How to frost a perfectly smooth cake with buttercream icing! Images and animated gifs with detailed instructions!

Next, we use the paper towel to finish smoothing any imperfections that are left from the offset spatula. Like I said above, I ONLY use Viva paper towels for this. They are the only paper towel I know of that doesn’t have raised patterns on it. You’ll notice that one side is smoother than the other – that’s the side you want against the cake.

I usually start with the top of the cake, since it tends to be rougher and need more work. Along with your paper towel, you’ll need the fondant smoother. Place the paper towel on the cake, smoothest side down, and rub in small circular motions with the fondant smoother to smooth out the icing. Press firmly and evenly, but not hard.

Tutorial - How to frost a perfectly smooth cake with buttercream icing! Images and animated gifs with detailed instructions!

Do the same with the sides of the cake, evening out any bumps or air holes.

Tutorial - How to frost a perfectly smooth cake with buttercream icing! Images and animated gifs with detailed instructions!

To help make sharper corners, place the paper towel on the top of cake, letting it hang over the edge and down the side. Placing your fingers against the side of the cake to keep the icing in place, use the fondant smoother to gently push the icing out towards to edge to help make that corner sharp. Do that anywhere you think the edges could use it.

Tutorial - How to frost a perfectly smooth cake with buttercream icing! Images and animated gifs with detailed instructions!

Keep working that paper towel and fondant smoother until you are happy with your cake.

Tutorial - How to frost a perfectly smooth cake with buttercream icing! Images and animated gifs with detailed instructions!

Next, I like to take my offset spatula and remove excess icing at the bottom of the cake and give it a clean edge. The spatula is placed at an angle so that nothing is actually touching the side of the cake, but just the bottom of the spatula side is grabbing the excess icing. Then pull the excess towards you and away from the cake.

Tutorial - How to frost a perfectly smooth cake with buttercream icing! Images and animated gifs with detailed instructions!

Use your other icing tip to pipe on your border. I used Ateco tip 844, but you could also use Wilton 1M, which is similar, or any other tip you prefer.

Tutorial - How to frost a perfectly smooth cake with buttercream icing! Images and animated gifs with detailed instructions!

Sprinkle with some spraaaankles!

Tutorial - How to frost a perfectly smooth cake with buttercream icing! Images and animated gifs with detailed instructions!

And you’re done! Put your cake on your favorite cake stand, add a few more sprinkles and dig in!! It’s time to eat all that hard work. 😉

Tutorial - How to frost a perfectly smooth cake with buttercream icing! Images and animated gifs with detailed instructions!

UPDATE 8/4/16: Here’s a video showing the technique on a recent cake!

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Tutorial - How to frost a perfectly smooth cake with buttercream icing! Images and animated gifs with detailed instructions!
Learn how to decorate Sugar Cookies with Royal Icing

Practice your smoothing technique on some of these delicious cakes:

Moist and Fluffy Vanilla Cake
(the recipe for the cake in the tutorial above!)
Moist and Fluffy Vanilla Cake! Such a soft, tender cake!

Strawberry Layer Cake
Strawberry Layer Cake full of fresh strawberries for flavor! Covered in sprinkles for a cute baby shower cake!

Best Chocolate Cake
Best Chocolate Cake - incredibly moist and chocolatey!

Bananas Foster Layer Cake
Bananas Foster Layer Cake - this cake is full of cinnamon, bananas and rum sauce! So good!

Cherry Chocolate Chip Cake
Cherry Chocolate Chip Cake - full of maraschino cherry flavor and mini chocolate chips!

Chocolate Oreo Cake
Chocolate Oreo Cake

Sparkling Cranberry White Chocolate Cake
Sparkling Cranberry White Chocolate Cake - super moist vanilla cake full of fresh cranberries, iced with white chocolate icing and topped with sparking cranberries!