Keto Sugar Free Baked Custard Tarts: 3.4g carbs. Because you’re worth it!
Such a classic, glorious, British dessert. Who can resist a custard tart? Beautiful, smooth, vanilla custard nested within sweet and crumbly pastry. You cannot beat a good custard tart. I say good because if you eat a bad one you can pretty much go off custard tarts in general for a pretty long time. I mean, it’s hardly fine patisserie, so I cannot fathom how one English high street bakery chain (that shall remain nameless) can sell a soggy pastry filled with a mix that tastes like sweetened scrambled eggs. Yuk!
If you proclaim to dislike custard tarts, you must have tried one of those awful things and decided… erm, thanks but no thanks. I wouldn’t blame you. It happened to me. But after I had tasted really good ones. So I wasn’t put off by the scrambled egg experience. Instead, I decided to start baking my own.
And, much to my surprise, it turned out to be really easy.
That, of course was in my previous life, a.k.a. life before keto days. So in went loads of sugar, milk and flour. Honestly, when I think back to how many carbs I used to scoff every single day, I can’t help but cringe 🙁
Still. That was in a distant past. And in my ongoing endeavour to transform all my old favourites, it was the custard tart’s turn. Ketofication accomplished.
The recipe has been tested and retested (you’ll never guess how many of these I’ve had to eat in the name of perfection…haha). And my Keto Sugar Free Baked Custard Tarts can make their glorious debut in cyber land.
A Super Easy Recipe that Won’t Let You Down.
Never tried making custard tarts because they look complicated? This recipe will surprise you. You really cannot go wrong with my Keto Sugar Free Baked Custard Tarts. The pastry couldn’t be simpler. The custard is a walk in the park. You don’t even have to separate eggs. You just need whole ones. For a custard without the pastry, my classic crème caramel is the one to make next.
Oh yes. I get quite fed up with unused egg whites which then require me to bake something else (I am frugal when it comes to food, and I hate wasting any of it). So I thought, what the heck, let’s try and make custard using a whole egg, instead of the yolk alone, as is customary. It worked. Happy days.
I don’t mean it’s OK for you to now go ahead and use whole eggs in ordinary custard, crème anglaise, or crème pâtissière. This one is baked, and the erythritol I use to sweeten has a drying effect. So I reckon that the extra liquid that the egg white provides is actually essential, in this particular recipe.
Want a proper pastry cream instead? My keto crema pasticcera makes one without any starch.
Ingredients for Keto Sugar Free Baked Custard Tarts.
First of all, the usual suspects. Erythritol and stevia to sweeten both custard and pastry. Also, Lupin and almond flour, plus butter, egg and lemon zest for the pastry. Egg, double (heavy) cream, vanilla paste and nutmeg for the custard. If you have a peanut allergy and would rather avoid lupin flour just in case, you can use almond flour alone.
You don’t need fancy kitchen gadgets, either. I don’t bother cutting out shapes to line my tart moulds, and I don’t use an electric whisk.
Below are my tart moulds. They have a removable base, which I find very useful. I’m afraid I cannot remember where I bought them, so I cannot provide you with a handy link.
Finally, did I mention it’s also a quick recipe? No? How could I forget that part! It will take you no time at all.
The hardest part is waiting patiently while everything cools down and sets…
Your Questions, Answered.
Coconut flour instead of lupin? It can work: start with a quarter of the amount and add more until the dough feels right. Coconut flour varies in how much liquid it soaks up, and the flavour won’t be quite the same.
One last tip: keep a close eye on the second bake. Ovens vary, and these babies burn very quickly.
Enjoy!

Keto Sugar Free Baked Custard Tarts
Ingredients
For the pastry
- 40 g unsalted butter room temperature
- 100 g ground almonds
- 30 g lupin flour
- 1 small egg
- 30 g erythritol
- ¼ tsp pure stevia powder
- 1 pinch fine Himalayan pink salt
- ½ lemon zest only, grated
For the custard
- 1 small egg
- 150 ml double cream heavy cream in the US
- 7 g erythritol 1/2 tbsp
- ¼ tsp pure stevia powder
- ½ tsp vanilla paste or make your own
- grated nutmeg
(Ingredients in green link to the products I use. More on keto ingredients.)
Instructions
To make the pastry
- Place cubed butter and all other ingredients in a large mixing bowl.
- Squeezing through your fingers, mix quickly until a dough is formed.
- Shape the dough roughly like a sausage, wrap it in cling film and place it in the freezer.
- Pre-heat oven to 160C static.
- Lightly grease 4 tart moulds (mine are 10cm diameter x 2cm deep).
- Take the 'sausage' dough, cut it in half and then cut each half into halves, so you have 4 equal quarters.
- Press each quarter dough into the base of your tart moulds and up the sides, working quickly to keep the butter cold.
- Bake for 12 minutes, then remove from oven and let cool completely.
- Once cooled, remove pastries from tart moulds and place them back in again (this is just to loosen them before the second bake).
- Keep refrigerated while you make the custard.
To make the custard
- Whisk whole egg with erythritol and stevia until nice and frothy.
- Put cream, vanilla paste and a generous sprinkle of nutmeg in a heavy-base pan over medium heat.
- When tiny bubbles start to appear where the liquid touches the pan sides (it will only take a minute or so), remove from heat.
- Pour cream slowly (or add 1 ladle at a time) onto the egg mix, whisking vigorously and continuously (this is to prevent the egg from becoming 'scrambled').
- Pre-heat oven to 160C again.
- Fill your pastry tarts with the custard, top with grated nutmeg and bake for 18 mins.
- Remove tarts from oven and let them cool, then refrigerate them for a few hours to set.
Notes
Nutrition
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Hi everyone! We’ve reposted this recipe for technical reasons, which is why the comments below are older than the post itself. All your comments and questions have moved over with it, so nothing is lost. Happy baking!
Absolutely gorgeous!! I substituted the lupin flour and it worked well. The only issue I had was that the custard was a bit runny, but I’m not sure if the cream got to a high enough temperature. I was taking real care not to let it burn. Will be making them again!
Pleased that you liked them, Cheryl. If the custard was a bit runny, it’s probably because UK double cream is higher in fat than heavy cream. Thank you for taking the time to post your feedback.
this is indeed mouth watering. Thanks for the share
Can I substitute coconut flour for the lupin flour? Any idea what the measurement would be? Thanks
You could start with 1/4 and then add until you get the right consistency. No precise substitution measurements because coconut flour can be more or less absorbent, depending on its fat content. You won’t get the same end flavour but it should work.
Hi,
I so glad I came across your website, I really like that you don’t seem to use a lot of alternate sweetener too. I can’t wait to make this recipe as I have a party to go to and need to take a dessert. I just have a couple of questions, I have a stevia and monk fruit blend, how much do you think I would need to use for the base given it is combined? And if I make one big tart do you think the cooking time would vary at all?
Thanks for your help ?
Karyn
Hi Karyn, sorry for not responding more quickly. I reckon the stevia and monkfruit blend will probably contain erythritol, so I would use the same quantity stated in the recipe. I would also not add extra time to either the blind baking or the custard baking. Reason being that there is no ‘rise’ involved, plus the base is pretty thin. A tip: keep a close eye on the second bake; oven ‘real’ temperatures can vary quite a bit, and these babies tend to burn very quickly.
Hi, me again. I’m looking at this recipe to make this weekend. I notice you have erytritol and stevia. Is it necessary to use both (as I don’t have any stevia)? Many thanks, Debbie
Hi Debbie, I often use erythritol and stevia in combination. Erythritol delivers a ‘cooling’ effect to foods and stevia has a bitter after taste unless used in minimal amounts. The two sweeteners together work in synergy and produce the best results, with undetectable ‘odd’ taste. By all means use erythritol on its own, but you may not be so keen on the end flavour. If you do, add extra erythritol, as it only has 70% the sweeteness of table sugar.
I am allergic to both almonds and coconut. Would it be possible to make the crust without the ground almonds?
Hi Rachel, I guess you could try sesame seed flour, or hazelnut flour. Are you also allergic to peanuts? If so, you should also substitute the lupin flour. Speaking of lupin, I wouldn’t use just that – it works best combined with other ‘flours’. I haven’t tested any of those alternatives, by the way, so I don’t know what the flavour would be like and you’ll probably have to adjust quantities, but I reckon it’s totally doable. Please let me know how you get on – other readers may find your changes interesting.
Can’t wait to try some of your recipes. Trouble is converting to American terms, cups and ounces rather then grams. I must loose weight or my doctor will put me on a higher dose of meds. I don’t want to deprive myself of sweets. I already use stevia and erythrol.
Hi Cherie, don’t give in to your dr, stick to Keto and you’ll lose the weight. Believe in yourself. You CAN do it, and Keto makes it easy. Sorry about the US weight conversion being problematic. But metric measures are way more accurate, so I recommend getting yourself some cheap metric scales and the problem is solved. Thanks for getting in touch and good luck! Reach out to me if you need any help or you get stuck. ?
The best thing to do with these lovely custard tarts, it’s just to make them, & eat them…it’s very easy to do that, as they’re gorgeous, & a joy to have for a change.
I thought when I started on my Keto diet, that these would be a treat I would need to say goodbye to, but thanks to Antya, not a bit of it. I’m not deprived at all, in fact, I like them better than the ” old style ” tarts..Well done again queenKETO X
Hi, Do you habe a sub for Lupin flour?
Hi Sean, yes, you can use the same amount of ultra fine almond flour. I use this one, if it helps. I use lupin because it has less carbs than almond flour and because it’s more neutral in flavour.
where can you buy lupin flour
If you’re in the UK https://geni.us/qk-sweet-lupin-uk
If you’re in the US https://geni.us/qk-lupina-lupin-flour
If you don’t have almond flour can you blitz almond meal sonits super fine ?
Hi there!Yes absolutely.
Thanks, they sound divine, will make them today and leave you a comment .
🙂
These look amazing. Thanks so much for sharing your recipes. I really love the “Ketofication” of great British favourites like these custard tarts and Yorkshire puddings. I’ll be trying out both.
Hello Katy, soooo sorry for this ultra late reply! I was just cleaning up my blog ‘bin’ and found your message (along with a multitude of spammer messages that are automatically diverted there). I don’t know what gave my blog bots the impression you weren’t legit…:( Anyway, thank you for your kind comment, and my apologies once again. Hope you’ll forgive me.