I’m going to show you step by step how to make and decorate a birthday cake so that you can surprise someone with a beautiful and delicious cake, even if you’ve never made a cake before! If you prefer to watch a video of this tutorial, scroll to the bottom of the page.
STEP 1: Bake your cake
The first step is to bake your cake! You can use any recipe you like – I’m using my Perfect Chocolate Cake and you can find the recipe and tutorial with step by step instructions here.
STEP 2: Cool and chill
After baking, let the cake layers cool completely and then wrap them in cling film or Saran Wrap and put them in the fridge for an hour or the freezer for 30 minutes, so that they firm up and become less crumbly.
STEP 3: Make buttercream
Meanwhile, make your buttercream. For an 8 inch cake you’ll need 500g of butter and 1 kg of icing sugar or powdered sugar, or if you’re in the US that’s 5 sticks of butter and one 2lb bag of powdered sugar. Mix them on the lowest speed of your mixer for 4 minutes and then add a teaspoon of vanilla and 2-3 tablespoons of milk to thin the buttercream out so it’s easy to stir and very smooth. I have a very detailed recipe and tutorial for my 4 Minute Buttercream here. Store the buttercream in an airtight container or cover the bowl with cling film or saran wrap until you’re ready to use it.
STEP 4: Build your cake
Now that your cake layers are chilled, it’s time to build your cake! Take them out of the fridge or freezer and unwrap them. If you have a turntable with a nonslip mat this next part will be easier but you don’t need one for this. You will need a ring of masking tape or a non-slip mat – I’m using a drawer liner that I bought on Amazon.
Place a cake board on the turntable. The tape or mat will stop the board from sliding around. Spread a dot of buttercream onto the middle of the cake board and press your first cake layer down onto it. The buttercream will act as glue to hold the cake in place securely.
Spin the turntable to check it’s lined up in the center of the cake board. Spread buttercream on top, or any other filling you want to use, going right up to the edges of the cake.
Place your next layer of cake on top, spinning the cake to check it’s directly on top of the previous layer so the cake is straight, and adjust it if you need to.
You can trim the tops of your cake layers if they’re domed, so that they’re flat, but if they’re a bit uneven like mine are it’s fine, just make sure you spread the filling on so it’s level and that will even everything out.
Continue alternating filling and cake to finish building your cake! The sides should be fairly straight but don’t worry about any imperfections – we’re going to completely cover this cake with frosting to give it smooth, straight sides.
Put the cake in the freezer for 15 minutes or in the fridge for 30 minutes to chill that dot of buttercream on the cake board to secure the cake firmly in place.
STEP 5: Crumb coat your cake
Now we’re going to give the cake a crumb coat. You’ll need your offset spatula and a frosting smoother – any kind is fine and I’ll talk about how to choose one in a minute.
Spread buttercream onto the top of the cake, using your offset spatula to spread it all the way over the edges of the cake to prevent air gaps there, and that will give you a nice flat surface on top of the cake instead of a domed top.
After covering the top, hold your offset spatula at a 45 degree angle and press down gently as you spin the turntable to flatten out the frosting on top of the cake.
Now spread buttercream onto the sides of the cake. I like to start at the top. You might notice the cake wobbling a little bit, especially if your cake is small like this 4” cake, or if the cake is tall, like this one is too. But that dot of buttercream on the cake board has chilled in the fridge so it’s sticking the cake to the card board and as long as you’re fairly gentle as you spread the buttercream on, you shouldn’t be able to detect the cake from that dot of buttercream so you won’t knock the cake over.
Spread the buttercream all the way down to the very bottom of the cake, right down to the cake board, so there’s no cake exposed anywhere. The point of this layer of frosting, called a crumb coat, is to trap any crumbs that come off the cake so that they don’t get into the final coat of frosting. It doesn’t need to be pretty, so the crumbs you can see stuck in this frosting are absolutely fine.
Smooth the crumb coat by scraping around it with a frosting smoother and I’ll cover this in much more detail in the next step, but just remember that the crumb coat is going to be totally covered up by the final coat of frosting so this really doesn’t need to be neat.
Ideally, the crumb coat will be fairly smooth but the most important thing about the crumb coat is that it covers up all of the cake to trap all of the crumbs. Put the cake in the fridge for about 15 minutes to set this crumb coat so it’s firm and next, it’s frosting time!
STEP 6: Frost your cake
While your cake is in the fridge, tint your buttercream whatever colour you like. I recommend using gel colours because they’re very concentrated so you can get bright and bold colours with just a few drops.
Take your cake out of the fridge and spoon buttercream on top and spread it around just like you did with the crumb coat.
Spread it over the edges of the cake and smooth it by spinning the cake while holding your offset spatula at a 45 degree angle and pressing down slightly.
Move down onto the sides of the cake, letting the frosting stick up above the top edge of the cake so that you can make sharp edges later. Spread back and forth with your offset spatula, scooping up more buttercream whenever you feel that as you’re spreading, the frosting layer is getting thinner.
You’re aiming for an approximately even thickness of frosting all over the cake but don’t worry too much about it because we’re going to do lots of touchups to even it out and get smooth frosting.
When the cake is covered with frosting, switch to a frosting smoother of any material – plastic, metal, or acrylic. I’ll show you the difference in a moment.
Hold the turntable with one hand and rest the frosting smoother down on the cake board to line it up straight against the side of the cake. This will prevent sloping frosting, which will make the cake look like it’s leaning to one side.
Gently press the frosting smoother against the side of the cake and spin the turntable, scraping around the cake with very little pressure until you can’t spin or reach any further. Then swipe the frosting smoother off, away from the cake. Each time you do this, reach as far as you can with your hand that’s spinning the turntable, so you get the longest scrape.
Hold the frosting smoother still and let the turntable do the work for you. After each scrape, use your offset spatula to wipe off any buttercream on your frosting smoother.
Use that buttercream to fill in any air pockets in the cake, which are indents or gaps where the frosting isn’t as thick as it is on the rest of the cake. Spread the buttercream over the gaps and then scrape around the cake again with your frosting smoother.
Remember to always press the base of the frosting smoother down onto the cake board so that the edge of the frosting smoother is upright.
Now let’s look at the difference between plastic, metal and acrylic frosting smoothers.
Plastic is flexible and easy to wipe clean after each scrape but it has the least sharp and smooth edge because plastic gets dented and damaged easily, so it won’t give you perfectly smooth frosting.
Metal is a bit heavier and sturdier so easy to line up straight against the cake by pressing it down on the cake board, and the edge is sharp so you’ll get nice smooth frosting with it.
Acrylic is also heavy and sturdy and this bevelled, diagonal edge is super sharp so you’ll get a beautifully smooth finish on your frosting. This one’s my favourite and you can get 10% off yours with the code BRITISHGIRLBAKES here.
Plastic would be my last choice of these three options but you can still get pretty smooth frosting with it so don’t panic if that’s all you have.
When you’re happy with the sides, use your offset spatula to tidy up the top edge by swiping from the outer edge fo the cake towards the middle and then continuing the motion to swipe off the cake, taking the excess frosting off the cake on your offset spatula. Scrape the excess buttercream into a bowl and then wipe the offset spatula clean using a paper towel so that you’re not dragging buttercream back onto your neat edges.
Continue all the way around the cake and as you’re tidying up this top edge, the pressure you’re applying down onto the cake will create a bulge around the top of the sides of the cake so when you finish, switch back to your frosting smoother and scrape around the cake one more time.
Tidy up the top edge, getting down to eye level to check that the edge is level all the way around the cake. Wipe any smudges of buttercream off the cake board by wrapping your finger in a paper towel and wiping around the cake and then it’s time to adds some finishing touches!
STEP 7: Finishing touches: Sprinkle border
For a sprinkle border, place your cake on its cake board on a caking tray and pour sprinkles around the base of the cake, onto the cake board.
The baking tray will catch any falling sprinkles so it’s MUCH easier to clean up afterwards! You can save 15% on your Fancy Sprinkles order with the code BRITISHGIRL15 by clicking here.
Push the sprinkles into the bottom inch or two of the frosting on the cake, using your hands or the back of a spoon or an offset spatula. It’s easier to do this now, straight after frosting the cake, while the frosting is still sticky so you don’t need to use much pressure to push the sprinkles into the frosting.
STEP 8: Finishing touches: Frosting swirls
The final finishing touch for this cake is to add some frosting swirls on top of the cake! You’ll need a piping bag and a star shaped tip like this 1M tip by Wilton.
Drop the tip into the piping bag and fold the end over and then scoop up all of the buttercream you scraped off the cake while you were frosting it and spoon it into the bag. Folding the top of the bag over before doing this means the end of the bag will stay clean so you won’t get buttercream all over your hands.
Push the buttercream down to the bottom of the piping bag and twist the end of the bag to push the buttercream tightly down to the tip so you won’t have to use as much pressure to squeeze it out of the bag.
Hold the bag over the cake and lower the tip down to the cake. Squeeze the bag to push the buttercream out, and spiral your wrist upwards to create a swirl, like you’d pipe onto a cupcake.
Each spiral should get tighter to make the swirl narrower as it goes up, and at the top, release your pressure on the bag as you swipe it away to leave a neat peak on the top of the swirl. I like to pipe the swirls opposite each other to space then out evenly on the cake and then fill in the gaps in-between and that way there aren’t any big spaces between swirls.
Tadaa! A beautiful birthday cake!
STEP 9: Serve!
I like to store my cakes in the fridge until four hours before serving them. The fridge keeps the frosting and decorations stable and then four hours is enough time to come to room temperature, when the cake and frosting taste the best!
In case you make your cake this tall, I have a quick tutorial on how cut tall cakes and check out my online cake school for LOT of online courses and classes on unique cake designs and techniques with step by step instructions that anyone can follow! Join my Club for access to every class as well as live online demonstrations and Q&A sessions!