Custard Cake With Blueberries

The custard layer especially is something else! It’s melt-in-your-mouth creamy but set enough to cut into neat slices. If the photo below has you drooling, read on …

Custard cake with blueberries

This cake came about as one of those “wouldn’t it be awesome if…….” ideas that suddenly materialise in my mind and I need to blurt out to anybody within earshot. I gestured enthusiastically as I described my vision of a cake and how I thought I could make it work. My excitement built as I started imagining how it was going to taste, until it bubbled over and I had to give it a go. So I made it. And the reality turned out even better than I imagined! It goes like this. Take a vanilla sponge base, perfumed with a subtle whisper of lemon. Smear a serious layer of custard on top. And I mean serious – as in equal in volume to the cake; we want lots. Finally, stud said custard generously with plump, juicy blueberries. Now bake that puppy! A mouthful of tender vanilla cake, creamy custard and a blueberry bursting in your mouth is one of the best things you will ever experience in your life. The thing that’s lovely about the custard layer is it’s set enough with cooking that you can cut perfect, neat slices like a cake. But the moment you eat it, the custard melts and floods your mouth with lush, creamy richness. And it is rich, but not overly so. It’s also definitely not too sweet with only 1/3 cup (60g) sugar in the whole custard layer. In case you doubt me, here’s proof of creaminess:

What you need to make Blueberry Custard Cake

I think you’re also going to love that there’s nothing unusual or gourmet called for in this recipe!

1. Custard layer

Here’s what you need for the custard layer:

Milk – full fat dairy please. Low fat will work but you will lack that rich mouthfeel. I’ve never tried non-cow milk, either. Egg yolks – I’ve pictured 4 eggs because that’s what you’ll probably need for the yolks called for in this recipe. Egg yolks give custard the silkiness, yellow colour, as well as thickening power. In this cake it also sets the custard so it doesn’t run everywhere when you cut a slice.Leftover egg whites – Here’s my list of what I do with them and all my egg white recipes can be found in this recipe collection. Vanilla bean paste – I use the paste because I like the little vanilla seed specks in my custard. However I choose paste over real vanilla beans in this and other custard recipes I make (such as Creme Brûlée, Flan Patissier, Creme Anglaise) because it doesn’t use up a whole bean. I I know it would personally irritate me to see a recipe calling for “half a vanilla bean” so I won’t do it to you either. Substitute with vanilla extract (no specks, but that’s cool). For a recipe like this, I think it would be a shame to resort to artificial vanilla essence, so avoid. Sugar – caster sugar / superfine sugar with finer granules is better as it dissolves more easily. However, regular / granulated sugar will be fine too. Cornflour / cornstarch – This thickens the custard along with the eggs. Similarly it also set the custard so it’s sliceable. Butter – This enriches the custard. You know butter is never an unwelcome guest, and this recipe is no exception!

2. Cake layer

And here’s what you need for the cake: Leftover egg whites – Here’s my list of what I do with them and all my egg white recipes can be found in this recipe collection. Substitute with vanilla extract (no specks, but that’s cool). For a recipe like this, I think it would be a shame to resort to artificial vanilla essence, so avoid.

Yogurt – Yogurt is a little baking trick that make cakes with a tender, never-dry crumb. It adds moisture to your batter without thinning it out like, say, milk. Which means you don’t need to use as much flour. And less flour means a more moist cake! Acidity in yogurt also reacts with and activates baking soda. However this is not applicable to this recipe as we are using baking powder rather than baking soda. I found baking powder made my yogurt batter rise more evenly (baking soda results in an unsightly hump!). Oil – Another cake moisture-improvement trick. While butter adds flavour, oil will gives you a moister result than butter. We really need good moistness in this cake, to be sure the cake stays tender even after the 45 minute bake time required to set the custard. Sugar – As above, superfine / caster sugar is preferred but regular / granulated will work fine. Lemon zest – Combined with the yogurt, the zest gives the sponge layer a hint of freshness. This distinguishes the cake component from the vanilla custard so the dessert is not so one-dimensional in flavour. This was a late addition and I really liked what it brought to the cake! Vanilla – I use vanilla extract here, not vanilla bean paste which I think is wasted because you can’t see the specks. Try to give artificial essence a miss because it tastes, well, artificial. Blueberries – Fresh or frozen. If using frozen, don’t thaw else it will bleed terribly when you mix it through the custard! Flour – Just plain / all-purpose flour. Baking powder – The rising agent in this cake. As mentioned above, I’ve used baking soda in the past for this batter but I found the cake got an unsightly hump in the middle. Baking powder gives it a much more even rise. Egg – Just one egg is all you need. Salt – Just a pinch. It’s good baking practice to add a little salt as it brings out the other flavours.

How to make Blueberry Custard Cake

There’s a few parts to this cake (custard, cake batter, layering), but I promise it is straightforward. Remember, it’s a rustic cake, so relax. We aren’t seeking perfect layers and placement of blueberries here! Acidity in yogurt also reacts with and activates baking soda. However this is not applicable to this recipe as we are using baking powder rather than baking soda. I found baking powder made my yogurt batter rise more evenly (baking soda results in an unsightly hump!).

1. Custard

Custard is so much more straightforward than most people realise. Custard is just milk thickened with cornflour/cornstarch and egg yolks, then baked in the oven to finish setting it. The only thing to watch out for is to avoid scrambling the eggs with the hot milk, but the recipe steps are designed to avoid this risk.

2. The simple cake batter

Oh this magic yogurt cake batter, used in so countless cakes on this website that many of you love so much! This method of gradually combining the hot milk with the egg yolks (tempering) is to make sure the hot milk doesn’t accidentally scramble the eggs. If at any point you feel like it’s thickening too fast, just take it off the stove and keep whisking. And if it starts to look lumpy as it is thickening, don’t fret, it does that sometimes! Just keep whisking and it will smooth out. The appearance of a lazy bubble is the signal that tells you when the custard is cooked enough. How much longer you cook it for after the bubble appears is determined by the volume of custard you’re making and the thickness you are aiming for. In our case, 30 secs whisking is right. Making ahead – The custard can be made the day before and refrigerated after it fully cools. In fact, the flavour of the custard improves overnight. It will solidify into a rubbery mass but don’t stress. Just use a handheld beater to beat it and watch as it magically turns into a creamy, dollop-able custard again!

3. Custard layering

The specific layering technique I use is all about achieving a straight and level line where the cake and custard interface, and an even distribution of blueberries throughout the custard. Fussy, who me? 😳

4. Optional blueberry burstage encouragement (& custard setting)

Serving, storing

I topped the cake with extra blueberries for photograph purposes only. You really don’t need to for serving, there’s plenty going on in the cake as it is. So much so that I like to encourage blueberry burstage by pulling the cake out of the oven 10 minutes before it’s done to deliberately burst some blueberries using a small knife. You don’t have to do this step. It’s entirely optional. (She says, unconvincingly) By the way, I’m sure you’ve figured it out by now but this recipe is specifically designed so the cake and custard both bake to perfection in the same time. To this end, there should be no browning on the surface of the custard. It should just be yellow with (hopefully) lots of blueberry guts seeping out and through it (are you counting how many times I use those kind of graphic descriptions??!😂) Overnight, and minimum 12 hours, is a safe bet! PS. If the custard is not fully set, while visually it may not present quite the same as what you see in the photos, let me assure it is still a heavenly eating experience. Some might even say a better one because you get big dollops of creamy custard. If you’re a little fussy like me, you can trim along the edges of the cake to make the edges smooth just using scissors. Don’t toss the trimmings, eat as you go. Think – blueberry fruit leathers (in scrappy, mini form.) As for serving, cut like a cake and serve like cake. The one thing I will really encourage though is to eat it at room temperature instead of fridge-cold. Chilled custard is nice. But room temperature custard is better. It’s creamier and tastier. Same goes for cake. So take the cake out of the fridge at least 30 minutes prior to serving, preferably 1 hour. If you can, slice fridge-cold then let the slices come to room temperature. The reason is you will get neater slices with sharper edges when the cake is cut cold, as the custard smears less on the knife. The cake is at room temperature in all the photos in this post, and when I cut the cake in the video below. I’d love to know if you try this cake. And if you do, tell me if where you sit on blueberry burstage! Did you take the extra step to encourage burstage? Do it! Do it! Do it! – Nagi x

Watch how to make it

Note: In this video I do not spread the custard on the cake properly! The better way to do it is as per the recipe card below – put big dollops around the edges of the cake and spread inwards. I will update the video after I make the cake again!