Apple Crumble Cake!

A deliciously light and autumnal apple crumble cake, with layers of brown sugar apple sponge, a crunchy cinnamon crumble topping, and the dreamiest cinnamon buttercream frosting!

This is my frosted, layer-style take on an apple crumble cake, so think a proper celebration bake rather than just a single-pan crumb cake. If you love apple crumble and you love cake, you guys are going to adore this one, it is honestly Autumn on a plate!

Apple baking

Just so you know before we start, this is a layered, frosted version of an apple crumble cake, so you get two lovely sponges, all that crumble, and the cinnamon buttercream holding it together. If you would rather keep things classic and low-key, you can absolutely bake the same mixture as a traybake in a single tin and just crumble-top it, but honestly the layered frosted version is the showstopper I make again and again!

I’ve been wanting to post something like this for a while… It’s well and truly Autumn now, the weather is changing, and its nearly Halloween. I saw a delicious looking post the other day of some apple crumble cupcakes, and this inspired me to use the countless amount of apples that have been growing in my garden recently.

I kid you not, I think we have had over 60 apples in just the past couple of weeks, and I can’t keep up with the baking. Some squirrels got to them, and some were eaten away at by bugs, but there were some absolute beauties which I just HAD to bake with – when you have something literally growing in your garden it’s rude not to use them.

I would say that it is important to use cooking apples because you want the apples to retain some texture when baking. The cake bakes for quite a while, so I would avoid using eating apples as they lose their texture, quicker. 

Ingredients you need and why

Here is a quick run through of what goes into this cake and why, so you know exactly what you are reaching for and what each bit is doing.

• Self raising flour – this is a proper UK-style sponge, so self raising flour is what gives it that lovely light lift. No need for anything fancy or any extra raising agent.
• Butter – block butter at room temperature is gorgeous in the sponge, but a baking spread works brilliantly too. For the crumble and the buttercream though, stick to block unsalted butter so they behave.
• Light brown soft sugar – I love this in the sponge because it brings a gentle caramel note that goes SO well with the apples and cinnamon. Caster or golden caster sugar are fine if that is what you have in.
• Eggs – I use six medium eggs for this one, but five large eggs will do exactly the same job.
• Cinnamon – 100% optional, but cinnamon with apple is heavenly and I would never skip it.
• Cooking apples – the star of the show. Cooking apples hold their texture through the long bake, which is exactly what you want here.

Best apples for apple crumble cake

The apples really are the make-or-break of this cake, so it is worth picking the right ones. The whole thing bakes for a good while, so you want an apple that can handle all that time in the oven and still give you those lovely soft-but-not-mushy pieces.

• Bramley apples – my go-to cooking apple here in the UK. They hold up beautifully and bring a lovely tartness against all that sugar.
• Other firm cooking apples – anything sold as a proper cooker will do the job and keep a bit of bite through the bake.

What I would steer you away from is soft eating apples. They cook down far too quickly over 45 to 55 minutes and you lose all that lovely texture, so you end up with wet, disappearing apple rather than proper pieces. Sticking with cooking apples really is the key lever for getting the texture spot on.

Crumble mixture 

I posted my recipe for a caramel apple crumble pie last year, and it was well and truly loved and I knew something crumbly and yummy would be ideal for this post. 

A crumble mix is very simple – it’s a simple mix of plain flour, sugar and butter. I always use plain flour in my crumble mix as you really don’t need to use anything else, there is no need for a raising agent. You can use caster sugar, light brown soft sugar, or anything you really have in the cupboard. 

It is important to use block unsalted butter and not a margarine in the crumble mix,  however, You need to add the ingredients to a bowl and rub the three ingredients together to a find breadcrumb like texture. If you don’t want to make it yourself, I don’t judge you buying a shop bought crumble mix. 

A couple of little cues to look for while you rub it together. You want your butter fridge-cold and firm, not soft or melty, because cold butter is what gives you those lovely craggy crumble clumps rather than a paste. Rub it in with your fingertips until it looks like rough breadcrumbs with a few bigger lumps still in there. If it ever starts feeling greasy or claggy, pop the bowl in the fridge for ten minutes to firm it back up, and that little bit of care is what stops the crumble melting flat into the sponge.

Cake mix

I went for a regular idea with my sponge, using a very similar one to my salted caramel drip cake using light brown sugar. I used a touch of cinnamon in the sponge to give it a bit of an autumnal kick, and it goes SO well with the apples it would be rude not to. 

• Butter – for a sponge mix, you can use a block butter at room temperature, or you can use a baking spread for the sponge mix
• Sugar – as mentioned above, I like using light brown soft sugar for this because it compliments the other ingredients. You can use caster sugar or even golden caster sugar if you preferred though. 
• Flour – self raising flour, of course. 
• Eggs – I use medium eggs, so I use six medium eggs, but five large would also work 
• Cinnamon – this is 100% optional, but I love the addition of cinnamon with apples. 

One thing worth clarifying: when I say 500g of cooking apples (peeled and chopped weight), I mean weigh them AFTER you have peeled, cored and chopped them, not before. Cut them into roughly 2cm chunks, a nice hearty bite rather than thin slices, because over the long bake they soften down to just the right texture. I fold those apple chunks straight through the sponge, and after testing this cake a good few times that really is the method that works best.

Baking the cakes 

I fold the apple mixture through the cake mix and then split the cake mix between two deep 8″ cake tins. I sprinkle most of the crumble mix on top of the two cakes, and then I bake the cakes in the oven. They take quite a while to bake at 45-55 minutes typically. 

I will admit I was a little unsure of how the apples would bake in this cake… Let’s just say, I tried part cooking the apples before I put them into the cake, but it didn’t work. After trying this cake four different times with this method, it’s safe to say that just coating the apples with sugar for a bit of sweetness, and baking them as they are is best. The amount of time that the cake is in the oven bakes the apples to the perfect texture (as you can see in the picture) and I wish I had just tried it the first time.

I tend to leave the cakes to cool fully in the tins to prevent handling the sponges too much – they can be more delicate due to the moisture. 

Here is exactly what I look for to know the cakes are baked through:

• The tops are golden and the crumble is set and lightly crisp.
• A skewer pushed into the centre of the sponge comes out clean, with no wet batter clinging to it.
• The sponges spring back when you gently press the top.
• The bake usually lands around 45 to 55 minutes, but always trust the skewer over the clock.

Watch for over browning: if the tops or crumble are colouring too fast before the middle is baked, loosely lay a sheet of foil over the tins for the last 10 to 15 minutes. It shields the top while the sponge quietly finishes baking through.

Buttercream frosting & decoration 

The spare crumble mix can be baked on a tray for 10-15 minutes until slightly golden, and used as decoration. You can also use fudge sprinkles (such as good combo with the apple and cinnamon again).

Using a cinnamon buttercream frosting was ideal for this as again, flavour heaven. I made it an easy buttercream frosting of 1:2 of unsalted block butter at room temp to icing sugar and it worked wonderfully with the tsp of cinnamon, and a touch of boiling water for smoothness.

I pipe the frosting onto the cake in swirls using my favourite piping tip like always – but you can slather it on instead if you prefer, or pipe it differently. 

Topping options

The cinnamon buttercream is my signature finish and it is what turns this into a proper celebration cake, so that is the version I will always come back to. That said, if you fancy something a bit more classic and low-key, you have options. A simple glaze made from icing sugar loosened with a splash of water or milk, drizzled over the crumble, is lovely. Or you can keep it really pared back and just dust the top with a little icing sugar. All three work beautifully, it just depends on how showstopping you want it to be!

Tips & Tricks 

Pan sizes

I use two deep 8″/20cm round tins for this cake, so you get two proper layers to sandwich together with all that buttercream.

Prevent overbrowning

Every oven runs a little differently, so start keeping an eye from around the 40 minute mark. If the crumble is browning faster than the sponge is baking, a loose sheet of foil over the top for the last stretch keeps everything even.

Cooling and slicing

Leave the cakes to cool fully in the tins before you handle them, as the sponges are lovely and moist and a bit delicate while warm. Once the cake is assembled, a sharp knife wiped clean between cuts gives you the neatest slices.

Storage and freezing

This cake will keep in an airtight container for up to 3 to 4+ days. You can also freeze it for 3+ months if you want, just let it defrost fully before serving.

Tools you need

Nothing fancy, here is what I reach for:

• Two deep 8″/20cm round cake tins
• An electric hand or stand mixer, or a good arm muscle
• A big mixing bowl for rubbing in the crumble
• My favourite piping tip and a piping bag (or just a palette knife to slather it on)

Short on time? A ready-made crumble mix works perfectly well here and does save a bit of faff. You will just still need to bake it on top of the cakes in the same way, and bake off the spare the same way too.