Keto Sugar Free Lemon & Blueberry Madeira Cake. NUT-FREE, DAIRY FREE and absolutely fabulous!
A scrumptious Lemon Cream Drizzle adds a touch of luxury, although it is optional. If you prefer traditional, plain Madeira, omit the blueberries and you’ll reduce the carbs even further. The simplicity and ease of this recipe does not detract from a result that is simply outstanding.
If you’re keen to reduce your dairy intake, despite your keto lifestyle, or you need to keep dietary calcium to a minimum, this cake recipe is ideal. I’ve used coconut flour, which isn’t a ‘nut’ in the botanical sense (read HERE for further info) and has very little calcium content. Extra virgin olive oil substitutes butter, further reducing the calcium.
You might be thinking: Hold on a minute! Isn’t calcium necessary? Well, it is. But not too much of it.
The Dietary Calcium Myth

For ages we’ve all been led to believe that calcium is good for you. ‘Drink more milk‘ they said… ‘otherwise you’ll be calcium deficient and your bones will suffer‘. Sadly, just like the ill-conceived fat>cholesterol>cardiovascular disease hypothesis, this ‘eat more calcium’ propaganda was always based on sophistry and scaremongering. It had no scientific foundation, and was designed to benefit the dairy industry, not the public. Quite like the ridiculous 5-a-day idea created by fruit and veg growers several decades ago. Eventually, with so many consumers seeking non-dairy options, calcium enriched foods had to be created – in order to continue to perpetuate that fallacious dietary advice.

More and more recent studies are showing that calcium intake has no bearing on osteoporosis prevention. Too much calcium, on the other hand, can lead to hypercalcaemia, and potentially cause an array of health issues including kidney and cardio vascular disease.
On very low carb diets such as keto, dairy, nuts and green vegetables are every-day staples that contain very high amounts of calcium. Think parmesan (cheesy recipes), mozzarella (fathead dough), sesame seeds and almonds (very common in keto-baking), kale and spinach, for example. Moderate consumption wouldn’t be an issue for most people, but in some, it may become a problem. If you’re supplementing with very high doses of Vitamin D3 (for example, because you’re following the Coimbra protocol to address an autoimmune disease), this can cause excess blood calcium and could eventually lead to serious kidney damage. In this case, avoiding high-calcium foods is essential.

Keto Sugar Free Lemon & Blueberry Madeira Cake is VERY LOW-CALCIUM
This one-bowl recipe takes literally a few minutes to prep. Once you’ve whipped the eggs and added all ingredients, you’re ready to get baking. Omit the blueberries, and you’ll have a more traditional Madeira cake with fewer carbs.
If you fancy my optional lemon cream drizzle, replacing dairy cream with coconut cream will keep the recipe dairy-free and lower in calcium.
Enjoy!
- Yield: 8 slices
- Serving: 1 slice
- Calories: 191
- Fat: 17g
- Net Carbs: 2.6g
- Protein: 6g

- 4 jumbo eggs (260g total)
- 100g extra virgin olive oil (U.S. option HERE)
- ⅛ tsp fine Himalayan pink salt (U.S. option HERE)
- 1 organic, unwaxed lemon (juice and zest)
- 1 tsp lemon extract (U.S. option HERE)
- 60g erythritol (U.S. option HERE)
- ½ tsp pure stevia powder (U.S. option HERE)
- 20g oat fibre (U.S. option HERE)
- 80g fine coconut flour (U.S. option HERE)
- 2 tsp baking powder
- 65g blueberries
- 100g double cream
- 1 TBSP Sukrin icing 'sugar' (U.S. alternative HERE) (or Make your Own)
- 1 organic, unwaxed lemon (juice and zest)
- pre-heat oven to 160°C fan (180C static).
- whisk eggs until tripled in volume, add olive oil and whisk again to emulsify.
- add all other ingredients except blueberries, mixing well between each addition - the mix should be quite dense, but should fall off a spoon: add a little coconut milk if too dry.
- gently fold in the blueberries, then transfer the cake mix to a baking loaf tin lined with non-stick oven paper.
- bake for 35-40 mins, until a skewer inserted in the middle comes out clean.
- to make the (optional) lemon cream drizzle: simmer the cream and icing 'sugar' for 5 minutes until reduced, let it cool down, then add lemon zest (1 whole lemon) and juice (1/2 lemon) - the lemon cream will become thicker as it cools.
- once the cake has cooled down completely, remove it from the loaf tin, peel away the paper and transfer it to a serving plate.
- spoon the lemon cream into a piping bag, snip the end (no nozzle necessary) and decorate your cake as you wish.
Macros are for cake without lemon cream drizzle.
For plain cake (without blueberries) NC = 1.7g per slice.
The best way to ensure accurate measurement of ingredients is with Metric Kitchen Scales. They are inexpensive and take up very little space. Click HERE for the ones I use. For U.S. option click HERE.
Your feedback matters to me! Please leave a comment below. If you try this recipe, you’ll make my day by sharing a photo on social media with the hashtag #queenketo. Thank you! 🙂

Hi there,
Is it possible to replace the erythritol with stevia?
Thanks!
Eva
Hi Eva, erythritol isn’t just for sweetening, it provides bulk and helps absorb liquids, so you do need to use it. Pure Stevia (what I use is 100% stevia – not a mix) is very bitter when used in high quantities, and especially in baking, so I most certainly wouldn’t recommend it. I add it to increase sweetness and minimise the erythritol needed for a given recipe. If you can’t consume erythritol, I suggest you find an alternative, but NOT ALLULOSE, as it burns too quickly so isn’t ideal for baked goods.
Hi Antya,
I’m planning on making this with a little tweaking to be Lemon Poppyseed Pound Cake, but I don’t have any oat fibre on hand. I’m assuming that the oak fibre is there to mimic gluten found in normal flour, or do I have that wrong? Would psyllium husk, or even lupin flour be an alright substitution?
Thanks!
Hi Wendy, I use oat fibre for three reasons: to add bulk, to lighten textures, and to reduce carbs (as it’s carb-free).
It doesn’t mimic gluten (that’s xanthan gum’s job). So yes you can substitute with a different type of flour you have to hand. You may end up with a denser result, but still good.
If not on this occasion, I highly recommend you buy this brilliant ingredient, not just for the reasons above – it’s also perfect for dusting work surfaces when you’re rolling out pastry, etc. as it has the best texture for that purpose (coconut flour is too drying and granular, nut flours are too oily and also grainy unless of the super-fine and defatted variety).
Hi Antya
Great recipe. Following a low carb diet for past eight months I’ve tried lots of recipes and had difficulties with US recipes and the inevitable difference in ingredients. Very glad to have found your site, cake turned out beautifully as have Yorkshire puddings made today!! Stocked up on all different flours so looking forward to trying lots more of your recipes. Thank you. Fran
Hi Frances! You’re very welcome! And thank YOU for taking the time to leave your feedback. Hope you’ll enjoy more of my recipes.
Hi could I use dried coconut (dessicated) instead of oat fibre please (UK) thanks a lot
Hi Janet, desiccated coconut will change its flavour and texture a bit, but I guess it would work. Let me know how it turns out 🙂