How to make a Harry Potter cake

Know a Harry Potter fan? Get this cake in the oven ASAP!

To start, you need to bake an 8 inch square cake. I made a chocolate cake and filled it with a chocolate ganache buttercream. See link below for an amazing chocolate cake recipe.  To make the cake look like a book, I carved a ‘V’ into the top of the cake and trimmed away the edges on the outside. NEVER carve a warm cake, it will make an absolute mess and you’ll regret it. I tend to make my cakes just before I go to bed and let them cool overnight for carving in the morning. Once the cake is suitably carved, add  buttercream inside and smother the remaining buttercream on the whole exterior (also known as the crumb coat). Crumb coats are used to keep the cake moist and act like a glue for the fondant overlay.


I always have about 2kg of fondant icing in my kitchen on any given day. You never know when you’re going to make a last minute masterpiece. To ice the cake, roll out your fondant on a clean surface until it’s big enough to cover the cake. Make sure it’s not too thin as you don’t want buttercream bursting through the sides. Trim the excess sugar off and roll it out again to make a big rectangle. Cut a rectangle that sits perfectly on top of the iced cake – this layer will be the crumpled open pages on top. Curl up the corners and sides of the fondant to make it look a bit scruffy. Use a blunt knife to score lines into the sides of the cake to make up the pages. Dust the whole cake in cocoa powder  with a pastry brush.  At this point, my kitchen looked a state but it was SO worth it.

The trick to a professional looking cake is the cake board. To make the illusion of floorboards, I coloured some fondant with brown food dye and then kneaded until it looked mottled. I rolled and cut it into long rectangles and jigsawed them together. So simple and effective. Finish off with a ribbon around the outside of the cake board and pin it in place.

To make the fondant owl, I made a snowman and added simple shapes to make up the features. Circles for eyes and triangles for the tail, beak, ears and claws. I diluted coloured pastes to make paint and brushed on a few details. I used liquid glucose to glue it all together. Don’t drop liquid glucose on your carpet. Enough said.

The HP glasses were made using black fondant mixed with Tylo powder. Tylo powder is a fabulous medium used to make fondant harden faster whilst still being pliable. Without the Tylo powder, the glasses would have been wonky and wilted. I made a long fondant sausage and cut it up and rolled it into circles for the eyepieces. Straight pieces made up the earpieces and were stuck together with more glucose. Again, for the time turner I used sausages of fondant to make it the right shape. I used the left over brown fondant from the floorboards to make a wand and gave it a black handle. The Ravenclaw scarf was created by cutting navy and white rectangles out and rolling them together until they bonded. A Ferrero Rocher makes a fabulous golden snitch and and just needed some yellow fondant wings added to it! I piped extra details on to all the models to give them professional cartoon look.

To pipe the birthday message, I googled the font used for the films and copied it onto the cake. Before piping any letters, I scored the outline into the fondant using a pin and then piped over it. If you make a mistake, let it dry and chip it off. Sorted.


There you have it, a Harry Potter birthday cake. A very happy birthday to Naomi! And big thanks to Naomi’s mum for asking me to make it.



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