This is a very special cake from the Harry Potter books that is very dear to me and my childhood that I've always wanted to make. This iconic chocolate cake is Harry Potter's birthday cake that he received from Hagrid on his 11th birthday.
'Anyway - Harry,' said the giant, turning his back on the Dursleys, 'a very happy birthday to yeh. Got summat fer yeh here - I mighta sat on it at some point, but it'll taste all right.'
From an inside pocket of his black overcoat he pulled a slightly squashed box. Harry opened it with trembling fingers. Inside was a large, sticky chocolate cake with Happy Birthday Harry written on it in green icing.
Harry Potter and the Philosopher's Stone

As a book loyalist, one of my pet peeves about the first Harry Potter movie was how they implied that Hagrid couldn't spell. If you're familiar with the iconic pink birthday cake with green icing shown in the movie, you will have probably noticed that the writing on the cake reads "Happee Birthdae Harry" instead of what was actually originally written in the book.
The book's description of the cake also never mentioned the colour of the cake, only the green icing. I loved the movie's rendition of the pink frosting but with the book's spelling. And that's how I ended up with this version of Harry's cake!
This rendition of Harry Potter's 11th birthday cake has soft and fluffy buttermilk chocolate cake layers, creamy chocolate ganache, pink cream cheese frosting, and green lettering. It's not too sweet due to the dark chocolate but decadent enough thanks to the layers of ganache. It made me so incredibly happy decorating and eating it and I hope it makes you feel the same way! Happy birthday Harry!
How to make Harry Potter's birthday cake
Prep oven & cake pans: Preheat oven to 350°F and line the bottoms of three 6” cake pans with parchment paper rounds. Set aside.
Mix dry ingredients: In a large mixing bowl, stir together flour, brown sugar, granulated sugar, cocoa powder, espresso powder, baking soda, and salt. Set aside.
Add wet ingredients to dry: In a separate large bowl, whisk together melted butter, oil, eggs, and buttermilk until the eggs have broken up. Pour this into the bowl of dry ingredients and mix on low speed with a hand mixer until mostly combined.
Mix in hot water: With the mixer on low speed, slowly stream in hot water and mix until batter is smooth and glossy. Don't overmix.
Bake cakes: Divide batter into cake pans until about ⅓ full. Bake cakes for 35-40 minutes or until a toothpick inserted in the middle comes out mostly clean. Let cakes cool for 10-15 minutes before running a knife around the edges of each cake pan and flipping them out onto a wire rack.
Level cakes: Remove the parchment paper and let cool completely. With a serrated knife, cut off the domed tops of each cake layer until each layer is flat and about the same height.
Heat cream: In a small pot or microwave, heat the whipping cream just until it comes to a simmer. Pour over the chopped chocolate in a small bowl and let sit undisturbed for about 2 minutes.
Stir ganache: Stir the ganache until the chocolate has all melted and combined with the cream to create a glossy and thick ganache. Let ganache cool for about 10 minutes to thicken into a spreadable consistency.
Assemble cake: Place one cake layer down on a turntable. With an offset spatula, spread a thick layer of ganache on top of the cake layer and smooth to the edges. Place the second cake layer on top and repeat.
Make cream cheese frosting: In a mixing bowl, use a hand mixer to beat softened cream cheese until smooth. Add in whipping cream, powdered sugar, and vanilla extract and beat until smooth and creamy, about 3-5 minutes.
Add food colouring: Divide out a small amount of frosting into a small bowl. Add pink food gel to the larger amount of frosting and green food gel to the small bowl. Stir until thoroughly mixed.
Frost cake: With an offset spatula, spread a thin layer of pink frosting on the sides and top of the cake as a crumb coat. Chill cake in the fridge for about 30 minutes. Finish frosting the cake by spreading a thick layer of pink frosting all around the cake and smoothing the sides with a bench scraper. This doesn't have to be perfect! Transfer the green frosting to a piping bag and cut the tip off. Pipe 'Happy Birthday Harry' on the top of the cake.
Frequently Asked Questions
This cake can be stored wrapped in plastic wrap or in a cake container in the fridge for 3-5 days.
Yes, you can freeze leftovers of this cake. Wrap them well in plastic wrap and freeze for up to 1 month. Thaw in the fridge overnight before eating.
Yes, you can make the chocolate cake layers in advance and store them in the fridge for 1-2 days or freeze them for up to 1 month before assembling the cake. The chocolate ganache and cream cheese frosting should be made fresh on the day you assemble the cake.
Absolutely! The book does not describe what the actual frosting is so you can also use American buttercream or Swiss meringue buttercream instead of cream cheese frosting. Just add the same pink food gel colouring to the frosting.
Other layer cake recipes to try
Recipe
Harry Potter's Birthday Cake
Ingredients
Chocolate Cake
- 200 g all-purpose flour
- 100 g brown sugar
- 100 g granulated sugar
- 75 g cocoa powder
- 1 teaspoon espresso powder
- 1 ½ teaspoons baking soda
- ½ teaspoon salt
- 115 g unsalted butter, melted
- 100 g flavourless oil
- 2 large eggs, room temperature
- 225 g buttermilk
- 120 g hot water
Chocolate Ganache
- 150 g dark chocolate, roughly chopped
- 200 g whipping cream
Cream Cheese Frosting
- 250 g cream cheese, softened
- 125 g whipping cream
- 75 g powdered sugar
- 1 teaspoon vanilla extract
- pink and green food gel
Instructions
Chocolate Cake
- Preheat oven to 350°F and line the bottoms of three 6” cake pans with parchment paper rounds. Set aside.
- In a large mixing bowl, stir together flour, brown sugar, granulated sugar, cocoa powder, espresso powder, baking soda, and salt. Set aside.
- In a separate large bowl, whisk together melted butter, oil, eggs, and buttermilk until the eggs have broken up. Pour this into the bowl of dry ingredients and mix on low speed with a hand mixer until mostly combined.
- With the mixer on low speed, slowly stream in hot water and mix until batter is smooth and glossy. Don't overmix.
- Divide batter into cake pans until about ⅓ full.
- Bake cakes for 35-40 minutes or until a toothpick inserted in the middle comes out mostly clean.
- Let cakes cool for 10-15 minutes before running a knife around the edges of each cake pan and flipping them out onto a wire rack. Remove the parchment paper and let cool completely. With a serrated knife, cut off the domed tops of each cake layer until each layer is flat and about the same height.
Chocolate Ganache
- In a small pot or microwave, heat the whipping cream just until it comes to a simmer. Pour over the chopped chocolate in a small bowl and let sit undisturbed for about 2 minutes.
- Stir the ganache until the chocolate has all melted and combined with the cream to create a glossy and thick ganache. Let ganache cool for about 10 minutes to thicken into a spreadable consistency.
- Place one cake layer down on a turntable. With an offset spatula, spread a thick layer of ganache on top of the cake layer and smooth to the edges. Place the second cake layer on top and repeat.
Cream Cheese Frosting
- In a mixing bowl, use a hand mixer to beat softened cream cheese until smooth. Add in whipping cream, powdered sugar, and vanilla extract and beat until smooth and creamy, about 3-5 minutes.
- Divide out a small amount of frosting into a small bowl. Add pink food gel to the larger amount of frosting and green food gel to the small bowl. Stir until thoroughly mixed.
- With an offset spatula, spread a thin layer of pink frosting on the sides and top of the cake as a crumb coat. Chill cake in the fridge for about 30 minutes.
- Finish frosting the cake by spreading a thick layer of pink frosting all around the cake and smoothing the sides with a bench scraper. This doesn't have to be perfect!
- Transfer the green frosting to a piping bag and cut the tip off. Pipe 'Happy Birthday Harry' on the top of the cake.
Harry
Happee not happy
Gail Ng
Actually, in the book Hagrid can spell and it's "happy".
Christina
Hi there! I've been trying to find out why there are squiggly cuts in the icing. I can't seem to remember. Do you know?
Gail Ng
Hagrid said he sat on the cake at some point so I'm quite sure it's just the result of being roughed up in his pocket during his trip to Harry or a baking/decorating mishap since he said he baked it himself!