The perfect birthday needs the perfect birthday cake. One that tastes delicious and is just the right size to feed all of your guests.
This vanilla cake calculator will give you the ingredients you need for any size of cake tin as well as the answers to lots of other FAQs to help you get your cake just right.
One post on my blog that’s always popular is my all-in-one vanilla sponge birthday cake. It’s the recipe I use for almost all of my family’s birthday cakes and I absolutely love the idea that people are making and enjoying this on their family birthdays too.
However, it seems that popularity comes with lots of questions and I’m finding similar ones coming up again and again. People have told me that they’ve been scrolling through the comments to see if I’ve answered the questions before but with over 125 comments and counting it cannot be easy to spot the answer you’re looking for in amongst everything else.
To try and help you all out I thought I’d pull together a quick post to answer all of your birthday cake FAQs as best I can and of course if I find new questions popping up in future I’ll add them in here.
Frequently Asked Questions
What ingredients do I need to make this cake in a different size?
What temperature should I bake the cake at?
How long should I bake my cake for
Can I bake two layers in one deep tin?
Can this recipe be used to make cupcakes?
Can this cake be used to make tiers?
How far in advance can you make the cake?
Can you freeze the cake?
Can I use butter instead of margarine?
Can I substitute plain flour for self-raising flour?
What size eggs should I use?
Can I make this cake gluten-free?
How much fondant do I need to cover my cake?
What ingredients do I need to make this cake in a different size?
The most comment question I’m asked is how to calculate the quantities to make the cake in a different size. To help you I’ve built this handy little calculator (I’m quite proud of myself for getting this working actually 🙂 ).
All you need to do is pop your tin size and the number of layers of sponge you want in your cake into the green boxes and it’ll tell you what you need. The first calculator is for a round tin and the second is for a square or rectangular tin.
I’ve also calculated the ingredients needed to coat the cake in a layer of buttercream (with buttercream in between the layers too).
You need to enter the tin size in centimetres, if you only know yours in inches, simply multiply it by 2.5.
NOTE – I’ve not tested the cake in all possible sizes (I don’t have all those different tins for a start) so cannot guarantee success, However, as long as you don’t stray too far away from the original size I expect it should still work well.
Round Cake
- 0 g self-raising flour
- 0 tsp baking powder
- 0 egg(s)
- 0 g soft margarine or butter
- 0 g caster sugar
- 0 drops vanilla extract
- 0 tsp milk
- 0 g butter
- 0 g icing sugar
- 0 tsp vanilla extract Approx.
- 0 tsp milk
Square or Rectangular Cake
- 0 g self-raising flour
- 0 tsp baking powder
- 0 egg(s)
- 0 g soft margarine or butter
- 0 g caster sugar
- 0 drops vanilla extract
- 0 tsp milk
- 0 g butter
- 0 g icing sugar
- 0 tsp vanilla extract Approx.
- 0 tsp milk
What temperature should I bake the cake at?
You can bake this vanilla cake at the same temperature specified in the original recipe regardless of the size of tin you're using.
How long should I bake my cake for?
As long as you split the mixture into sandwich tins the cooking time will be the same as for the original recipe.
Can I bake two layers in one deep tin?
Yes you can. However it will take longer to bake.
If you put the mixture for two layers into now deep tin you'll need to bake the cake for 45-50 minutes.
Can this recipe be used to make cupcakes?
Yes, you can find the recipe to make this cake as cupcakes here.
Can this cake be used to make tiers?
My parties are all pretty small so I've never needed a cake big enough to justify tiers. It is quite a soft, light sponge and so I would expect it to be fine for 2 tiers but personally I wouldn't risk 3.
If you are planning on making two tiers remember to include some sort of support in the lower layer (strong straws or dowelling cut to the height of the cake, and also put the top tier onto a thin cake board the same size as the cake (this adds additional support and also stops the moisture from the sponge ruining the fondant on the bottom layer).
How far in advance can you make the cake?
I usually bake my cakes on a Thursday and decorate them on a Friday for a Saturday party. We only have small parties so there's usually some leftovers which have always lasted for a few days after the party.
Make sure you store it in an airtight container to keep it fresh and if the weather is particularly warm I'd suggest keeping it in the fridge.
Can you freeze the cake?
Yes, you can freeze the undecorated sponge. Simply wrap it in clingfilm or an airtight bag and pop it into the freezer. When you want to use it remove it from the freezer and then make sure it's fully defrosted before decorating.
Can I use butter instead of margarine?
Yes, just make sure you take the butter out of the fridge a little before you want to start baking to allow it to soften.
Can I substitute plain flour for self-raising flour?
I've only ever used self-raising (as I've always got it in the cupboard). Nigella suggests you can substitute plain flour by simply adding an extra 2 tsp of baking powder for each 150g of flour used (so for my original recipe you'd need an additional 3 tsp of baking powder).
What size eggs should I use?
I use whatever I have in the fridge! Most of the time that'll be medium eggs but it works just as well using large.
Can I make this cake gluten-free?
You should be fine to substitute the self-raising flour for a gluten-free self-raising flour. Also, double check that the brand of baking powder you're using doesn't contain gluten (some do, some don't).
How much fondant do I need to cover my cake
If you'd like an idea of how much fondant you need to cover your cake then head on over to my fondant calculator where it'll tell you for any size of round, square or rectangular cake.
FREE GRAMS TO CUPS CONVERSION CHARTS
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This post was originally published on 17th May 2016 and updated with an improved calculator and more FAQs on 11th July 2018.
Tara O'Neill says
I actually just LOVE this. And your chocolate cake calculator is awesome too. Ive made two wedding cakes now using this recipe and both have been 5 tiers. Tried and tested (with dowels and cake boards between each layer). It works and is a major crowd pleaser. love it! One note: this recipe doesnt like tall tins, it needs short tins, but its great though.
Jo Jarman says
After trying so many recipes for a lovely cake that turned out well, I made the vanilla and the chocolate cake to do a two-tier cake on the recommendation of a friend. Wow! It tasted just like I had had from a professional Baker that I had paid over a £100 for. It was amazing! Buttercreams too! I love lemon cake, and wondered if you could advise on adapting this to make a lemon version. Any help appreciated!
Thank you for the amazing recipes and the calculator function.
Stacey says
Hi,
I am hoping to use your recipe in a couple of weeks for my daughters birthday cake.
I’ve seen that it’s best to let the sponge settle overnight before decorating it.
I would be making the sponge on Monday evening, and then decorating it on Tuesday evening ready for my daughters birthday on Wednesday.
My question is, would the sponge cake be ok in a cake box for 24 hours or would it dry out too much? I don’t have an airtight container big enough.
Thank you in advance
Charlotte Oates says
Once the cake is fully cooled, wrap each sponge in cling film/cling wrap/saran wrap. This will stop the air getting to the sponge and drying it out. Aluminium foil would work if you don’t have cling film. Don’t stack the cakes if wrapped in foil as the pressure from another cake on top will encourage it to stick to the foil.
Phyllis says
I am making you birthday sponge in a 32 x22tin how long would it take to bake at 140 c please
Charlotte Oates says
I haven’t tested this specific tin size but as the tin isn’t significantly larger than the 30x20cm tin that I sometimes use, I wouldn’t expect the cooking time to be significantly different from the written recipe.
sandra says
Hi
I am trying to put my measurements in for a 22 cm square cake tin for the birthday cake with 2 layers but it will not calculate it.
Any help please?
Charlotte Oates says
I have just tried the calculation and it does seem to be working for me. Did you make sure to enter 22 in both of the boxes and then 2 for the layers? If you are still having problems, please can you let me know specifically what the issue is so I can further investigate.
Hetal says
Hi Charlotte. Would this cake need any support if I make it as a one tier, 4 layer cake? Ten inches.
Thanks
Hetal
Charlotte Oates says
Shouldn’t do, but you could add a few dowels or straws if you’re at all nervous.
Laura says
Hello- any idea how best to calculate the quantities for a 20cm hemisphere cake? Thanks
Charlotte Oates says
I don’t recommend making this cake in a hemisphere tin as the sponge is soft and make stick
Miriam Holley says
I would like to use your recipe for the all in one sponge for a birthday cake using a 12 inch round cake tin in one layer. Please could you send me the correct ingredient amounts please . Thank you …
Charlotte Oates says
If you scroll up this page you will find the calculator to help you with this. Enter 30cm for the tin size and 1 for the number of layers. The correct ingredient quantities will be calculated for you.
Ruth Whyard says
When naming buttercream the ingredients state ‘butter’. Do you use unsalted butter or salted butter? I always assumed you meant unsalted butter but more recently have tried using salted and I think I like it ☺️
Charlotte Oates says
I always use unsalted but there’s no reason not to use salted if that’s what you prefer. Buttercream can be very sweet so the salt in the butt would help offset some of that sweetness in the same way it works in salted caramel.
Shelley Hollingsworth says
I love your recipe so much. I have bought a number 2 baking tin for my son’s birthday cake next week. Is there a way I can calculate the recipe size I will need? Many Thanks
Charlotte Oates says
The best way is to work out the volume of the original cake tins and your 2 tin. Fill each tin with water, pour into a measuring jug and see what the volume of each is. If for example two sandwich tins held 3 litres of water between them and your 2 tin held 4 litres of water, you’d know to increase the contents of the original recipe by one third. I hope this helps.
Angela says
Hi
I want to make a splatter cake for my daughter
I’m going to follow your recipe but I’m not sure if I should chill or freeze the cake before adding the filling and fondent. Thanks Angie
Charlotte Oates says
As long as it is well chilled, you shouldn’t have any problems. You can use the freezer if you need to get well ahead or need to get it cool quickly.
Lyn says
I’ve put in the size of the cake tin I’ll be using for one layer 35cm round,
With no reaction at all when I press calculate.
Am I doing something wrong please?
Charlotte Oates says
I apologise that it looks like the calculator is not currently functioning correctly – I will be getting this fixed asap. Thank you for alerting me to the issue.
Menna says
hi, If I want to make 1 cake and cut it into 2 layers – when calculating the ingredients for the tin, shall I enter 2 layers or 1 ?
Thanks,
Menna
Charlotte Oates says
To get the correct quantities you would want to enter 2 into the layers calculation. But it is worth noting that the cooking time and temperature would need to be adjusted to take into account the depth of the cake. I therefore do not recommend making the cake this way.
Natalie says
Hello!
I’ve been using your recipe for birthday cakes for about 2 years. It’s brilliant and easy. Thank you! I normally use two 20cm round tins, which I then put together for one big cake. However, I’ve bought a rectangle cake tin because the cake I want to make next will look better this shape. The tin is 35cm x 24cm x 6cm. I’m happy for this to be a plain sponge, covered in buttercream and fondant but with only one layer and therefore, no buttercream filling. Will this work? I hope this makes sense!
Charlotte Oates says
It sounds like that will work perfectly.
Pandora says
The recipe says “line the cake tins” but it doesn’t mention greasing them. Is just lining them enough?
Charlotte Oates says
It will depend on what you are using to line your tin. My recommendation is to use bake-o-glide reusable liners which do not need any additional greasing.
Sooz says
Hi. Whenever I make sponge cake with baking powder it tastes horrible. Why is this? I tend to leave it out now. Thanks
Charlotte Oates says
It may be that some people are simply more sensitive to the taste of baking powder.