This Chocolate Orange Traybake Cake (also known as a sheet cake) is a super easy recipe and great for feeding a crowd of chocolate orange lovers! The chocolate orange sponge is soft and has a nice thickness to it. I don't like it when traybake cakes are really thin, so you won't be short of lovely moist cake in this traybake! On top is a smooth chocolate orange buttercream, some vibrant orange zest and Terry's chocolate orange segments (they're an absolute must!) This traybake is a great crowd pleaser for family gatherings, parties and bake sales.

Ingredient Tips & Equipment Information

Make sure all your ingredients (particularly the butter and eggs) are at room temperature before you start baking.
I used a baking spread for the cake and unsalted butter for the buttercream.
For the best flavour, make sure to use a good quality orange extract and not an essence. If you can't get hold of orange extract, you can use the zest of two oranges in the sponge. You can't replace it with anything in the buttercream unfortunately, orange juice is not strong enough to get orange flavour in the buttercream, you would have to use a lot and it could make the buttercream sloppy. What I would suggest instead is mixing 100g melted chocolate orange into the buttercream, then adding 1 - 2 tbsp milk to loosen it if it's too thick.
You will need a 12" x 9" traybake tin for this recipe. However, if you want to make it in a 9" square tin, check the recipe notes for the measurement details.
Although I provide cup measurements, I highly recommend weighing your ingredients out using digital kitchen scales*. It is the most accurate way to measure ingredients and will ensure the best results. Digital scales are very low cost and can be purchased for around £12 ($16.50) .
For teaspoon (tsp) and tablespoon (tbsp) measurements, please use measuring spoons* and not the type of spoons you eat with. Again this will ensure accuracy and provide the best results.

For the full recipe with measurements, head to the recipe card at the end of this post.

How to make Chocolate Orange Traybake Cake

To make the cake, mix together the butter and sugar. Then whisk in eggs, orange extract and milk. Add self raising flour, cocoa powder and baking powder, and gently whisk in.

Spread the mixture out into the tin and bake the cake for 25-30 minutes or until a thin skewer inserted in the centre comes out clean.

Make the buttercream by mixing butter, icing sugar, cocoa powder, orange extract and milk together until smooth. Spread it over the cooled cake and decorate with orange zest and chocolate orange pieces.

How long does the cake last for and can you freeze it?

The cake will last for 3-4 days in an airtight container in a cool place. You can freeze both the cake and the buttercream. To freeze them separately, wrap the cake well in cling film or put it in an airtight container. The buttercream can be frozen in a sealed tub. To freeze the cake decorated (I don't recommend freezing the orange zest decoration), freeze on a plate until frozen solid, then carefully wrap in cling film. Remove the clingfilm when you take the cake out of the freezer to defrost, as if it defrosts with it still on it could damage the appearance of the buttercream.

Can you make this cake with plain/all purpose flour?

Self raising flour, which is very commonly used in the UK where I am based, already contains a raising agent and a little salt too. Therefore if you want to swap it for plain or all purpose flour, you will need to add some additional baking powder and also a little salt if you like. Some people like to add salt to cake recipes and some don't, so I'll leave that up to you as it won't affect the bake. The general advice is to add 2 teaspoons baking powder (a measuring teaspoon, not the kind you stir your coffee with) per every 200g plain or all purpose flour. So for this recipe you'd need to add 2 teaspoons baking powder. Please note, I have not tested this recipe using plain or all purpose flour.

What size tin do you need for this cake?

This recipe is best made in a 12" x 9" (36.5cm x 26cm) traybake tin with deep sides (4cm or 1.5"). However, if you'd prefer to make it in a smaller 9" square tin, check the recipe card notes section for details on how to change the measurements and baking time.

How many people does this cake serve?

It completely depends how you slice it up, which is great because it makes this such a versatile cake for parties and gatherings. I love a big chunk of cake so I cut it into 12 slices, but for a party you may prefer to cut it into smaller slices so it feeds more people. You can cut into 16 slices, or even 24 slices. If you are doing smaller slices, cut it up before you add the chocolate orange segments on top so you don't have to try and cut through them.

What can you use instead of orange extract?

I get my orange extract from either the supermarket or Amazon, and I do recommend it for this recipe. If you can't find orange extract for the sponge and buttercream, you can use the zest of two oranges for the sponge. Orange juice is not strong enough to get orange flavour in the buttercream, you would have to use a lot and it could make the buttercream sloppy. What I would suggest instead is mixing 100g melted chocolate orange into the buttercream, then adding 1-2 tbsp milk to loosen it if it's too thick.

Can this cake be made gluten or dairy free?

Yes! For gluten free you can replace the self raising flour with a gluten free self raising flour blend. If you only have a gluten free plain flour blend, you will need to add baking powder. The general advice is to add 2 tsp baking powder per 200g flour, so for this recipe you'd need to add an additional 1 + ¾ teaspoons of baking powder. You may also like to add ¼ tsp Xanthan Gum for better texture. For a dairy free version, use a dairy free baking spread and a dairy free milk for the cake and the buttercream. Terry's Chocolate Orange is also not gluten or dairy free, so you will also need to use another type of orange flavoured chocolate.

Can this cake be made into cupcakes or a larger cake?

Yes, to make this recipe into cupcakes check out my Chocolate Orange Cupcakes recipe for details. Or for a larger cake you might like my Chocolate Orange Cake or my Chocolate Orange Drip Cake.

More tips for making the Chocolate Orange Traybake Cake:

I spread the buttercream onto the cake, but you could pipe it on if you prefer.
You could also drizzle some melted chocolate orange over the cake!
If you don't have Terry's Chocolate Orange where you live, or you can't get hold of it, just use any other orange flavoured chocolate treat like Lindt, Matchmakers, or orange Twirl.

Troubleshooting

If you have any questions about this recipe, or if something went wrong and you need help, please use the comment form below and I will get back to you. You can also get in touch with me on my Twitter, Instagram or Facebook. I'd love to hear from you!

Recommended equipment & ingredients*

*I earn a small amount of money if you buy the products after clicking on the links. You will not be charged anything extra for this. Thank you for supporting The Baking Explorer!

More chocolate orange recipes…