Froggle's Blog

Cool Harry Potter Themed Birthday Cake

Cool Harry Potter Themed Birthday Cake

How to make a Harry Potter Sorting Hat Birthday Cake


harry potter sorting hat birthday cake

My son is super into Harry Potter, so for his 8th birthday party, I decided to make him a sorting hat birthday cake.

Surprisingly, although time consuming, it’s a lot easier to make this birthday cake than you think.

I’ve outlined the process for you below: –


Harry Potter, Sorting Hat Birthday Cake Step by step guide:

Step 1:

First, bake several cake tins’ worth of cake, using those fairly shallow round, cake tins.

I went for a traditional sponge cake recipe, and did 7 layers.

The number of layers you use will depend on how big you want to make it and the height of each of your sponge layers.

For a bit of fun, I also used some harry potter themed food colouring colours to alternate the cake layers so they were different colours. It looks really cool when you cut into it afterwards) You simply add the food colouring into the mix before you bake it.


Step 2:

Once you’ve baked your cakes, allow them to cool down.



Step 3:

Then pile your layers of cake on top of each other with your choice of filling between each layer. I used a simple butter cream.

Ideally, do this on the board you plan to keep the birthday cake on, as once you start, its hard to move the cake after that. You want a big board  that will allow for the hat rim too.



guide to making a harry potter sorting hat

Step 4:

For making the ‘drooping’ bit, for the top of the hat, I used rice crispies and melted mini marshmallows. Simply melt some mini marshmallows in the microwave (use as big a bowl as possible so you can later pour in the rice crispies directly into the melted marshmallows, rather than trying to pour the melted marshmallows into the bowl of rice crispies (I tried that and it didn’t work. Lol))

Once your marshmallows are melted, pour come rice crispies in. I didn’t keep track of how much I used. I just poured it in and measured by eye.

Heads up – This bit was very messy!! I used my hands to mix the rice crispies and marshmallows together. In hindsight I wish I had used a spatula, but by that point it was too late. lol The mix stuck to my hands like glue!! Lol

Once mixed together, (either by hand or by spatula) you then need to ‘mould’ the rice crispy/ marshmallow mix into the shape you want, to go on the top of your cake.


Step 5:

Then apply a nice generous layer of buttercream, all over the outside of the cake and the rice crispy top, to seal the outside of the cake. As shown in the photo.



Step 6:

Get some brown icing (I used ready to roll icing). And roll it in your hands to create long snake like strands. You want the strands to be fairly thick, so they show up through the icing you apply later on. But not so thick they are too heavy to stick on to the cake and fall off.

Then apply the strands on the cake as shown in the photo. Plus a bigger bit for the nose. I also used some food or cake glue to help stick it in place and stop it coming off.



Step 7:

Personally I took a rest at this point and came back to finishing the cake the next day. I think this also helped for the next step outlined below.



make a harry potter birthday cake
applying the face to the harry potter sorting hat

Step 8:

Make sure the strands that make up the features of the face, are firmly fixed on before applying the main icing. It might be that you have to let the cake glue harden for a while before you can put the icing on. As I said, I left mine overnight.

Next roll a very large sheet of brown icing. I sprinkled icing sugar on the roller and on the table surface to prevent the icing from sticking to the table or rolling pin. You want the sheet you roll, to be large enough to cover the whole surface area of the hat (both width and height). Then carefully drape the sheet of icing over the front/ face of the hat. Then wrap the sheet around, so the 2 sides meet at the back. Don’t worry if it looks messy at the back. You can sort this later.

As you lay the icing onto the cake, start gently pressing into the icing where the face will be, so the features of the hat’s face start appearing. Again, don’t worry about tidying the back yet until you’ve done the face. But at this point you can see your kids birthday cake is starting to shape up nicely.

Once that’s done, you can start joining up the icing at the back so the cake didn’t look messy. I had to do a fair bit of trimming of the icing to tidy it up. I also need to do a bit of ‘icing patchwork’ by using a few extra little sheets of icing where the main sheet didn’t quite cover the back.

To join the additional icing ‘sheets’ together, or repair any tears, I continually pressed the bits together with a wet finger, or gently rubbed in little circles with a wet finger to smooth out all the kinks. This took a lot of time, and was rather frustrating, but I got there in the end.

I then left it all to dry.






Step 9

For effect, I used a very small amount of black food dye one the eyes and in the opening of the mouth. I dabbed a bit on my finger and rubbed it on the specific points of the cake.


Step 10

Next you’re going to add the hat rim to the birthday cake. Again I just rolled out some brown icing. I used 2 sheets, cut them to size and then joined them in the same way as outlined above.

The cake really starts to look cool at this point.




For fun, I added some pre bought harry potter themed cake toppers and decorations ( I didn’t make those).

Just before I brought out my kid’s birthday cake out, I also dabbed around the cake in places, with a wet finger, to give it a bit of shine in places, for effect.

The hat rim of the cake ended up draping over the board, which was not intended but it actually ended up looking quite effective that way.


Anyway, I do hope this birthday cake blog helpful. My son absolutely loved this cake!!! I am no cake expert but it came out looking amazing!

harry potter sorting hat birthday cake

What we are experts in though is kids entertainment. We specialise in kids party entertainment, so if you are looking for professional kids entertainers to give you kids a magical time do get in touch. Our entertainment includes things like: magic, themes, games, dancing, puppet shows, balloon modelling, science, discos, bubbles, and much more!!!

For party planning tips you can also check out our party tips page.

Happy baking!!


Check out what customers have said about our terrific children’s entertainers.


Watch one of our amazing kids parties in action!


Free printable invites & other stationary.
Or get our app to send invites via your phone.

Why Us?

See what makes us stand out from other children’s entertainers.