Calling all lemon lovers! This Keto Lemon Magic Custard Cake has an ethereal texture and bright lemon flavor that will make it hard to stop at just one slice!
This Keto Lemon Magic Custard Cake (or simply Magic Cake) is my first attempt at replicating the classic magic cake, which uses a single batter that separates into three layers during baking. In a typical magic cake, you end up with a dense bottom layer, custardy middle layer, and ethereal light and spongy layer on top.
This Keto Lemon Magic Cake produced a much lighter texture than the classic, which I didn’t mind at all. In fact, the contrast between the smooth custard and slightly grainy “cake” top, was so pleasing, that it was hard to stop eating them!
Because I was losing daylight, I didn’t cool this Keto Lemon Magic Custard Cake as long as I should have before cutting it into squares, but as you can see in the photo above, they were still plenty sturdy enough to hold and eat.
I’m on the fence about whether I preferred them fully chilled or not. The top was slightly crisp that first day, which I loved, but after spending the night in the refrigerator (a requirement due to the eggs) the top had softened from the moisture and had a more cake-like texture. Not a bad thing, but I really, really loved the contrast in textures in those first couple of hours out of the oven!
Because this Keto Lemon Magic Cake is pretty fragile, you’re going to want to bake it in parchment to prevent sticking, and so that you can easily lift it out of the pan when cooled, for easier slicing and serving. The dusting of powdered erythritol is optional, but does dress the cake up a bit, so I do recommend it.
If you’ve never had magic cake before, then you’re in for a treat with this keto version, which has a unique texture that isn’t quite cake, or flan, or custard, but a delightful combination of all three.
If you try this keto magic cake recipe, do report back and let us know how it turned out! Then, if you can’t get enough of all things lemon, try my wildly popular Keto Lemon Sour Cream Muffins next!
Keto Lemon Magic Custard Cake – Low Carb
- Total Time: 1 hour 25 minutes
- Yield: 16 squares 1x
Description
This Keto Lemon Magic Custard Cake has an ethereal texture and bright lemon flavor that will make it hard to stop at just one slice! Low carb and gluten free.
Ingredients
- 5 eggs, room temperature, whites separated from yolks
- 1 teaspoon vanilla extract
- 2/3 cup powdered erythritol
- 1/2 cup unsalted butter, melted
- 1 cup superfine blanched almond flour
- 1/4 cup coconut flour
- 1 3/4 cup unsweetened almond milk, room temperature
- 1/4 cup lemon juice
- 2 tablespoons grated lemon zest
Instructions
- Preheat the oven to 325 degrees Fahrenheit.
- Line a 8 x 8 square baking dish with parchment paper or foil.
- Beat the egg whites until stiff and set aside.
- Beat the egg yolks and sweetener together until light.
- Add melted butter and vanilla, then beat until smooth.
- Add the almond flour and coconut flour and beat until fully blended.
- Add the lemon juice and zest, then while beating slowly add the almond milk gradually until everything is well mixed.
- Using a spatula, fold in the egg whites a third at a time.
- Then whisk lightly with a fork for about 10 seconds, or until the batter is mostly combined, but still has bits of egg whites floating on top.
- Pour the batter into the dish, and bake for 70 minutes, or until the top is lightly golden and the cake is firm to the touch.
- Remove from the oven and cool for 1 hour, then refrigerate for 2 or more hours until completely set.
- Carefully remove from the pan and cut into squares.
- Garnish with powdered erythritol if desired.
- Store leftovers in an airtight container in the refrigerator for up to 1 week.
Notes
Approximate net carbs per serving = 2g.
- Prep Time: 15 minutes
- Cook Time: 70 minutes
- Category: Keto Dessert Recipes
- Method: Baking
Nutrition
- Serving Size: one 2" square
- Calories: 123
- Fat: 11g
- Carbohydrates: 3g
- Fiber: 1g
- Protein: 4g
Joan Snydmiller says
Fabulous recipe
Charlie says
Hi, could the almond milk be subbed with a cream/water mix?
Mellissa Sevigny says
The fat would be much higher and I don’t know what that would do to the texture of the cake.
Sarah says
This cake was soooo awkward to make. Everything looked and felt wrong. I anticipated horrendous results. HOWEVER!!! It came out quite nice. It has a weird texture and very “soggy”, but that was the point. Will make again.
Cherise says
Update: I flipped the cake upside down and baked for another 45 minutes and let it cool. It isn’t pretty but the texture is great and it’s damn delicious. My batter was very thin and sloppy, when I put it in the oven I told my husband I was worried. I’m not sure why it didn’t turn out, I measured everything precisely but I’m really happy with the taste and texture of the end result.
Cherise says
Mine was a wet soggy mess. Not sure where I went wrong but I’m sure it’s my novice kitchen skills.
MelissaB says
I liked the flavour (I made it as a breakfast substitute :) )- but it did NOT separate like a magic cake does. I followed the directions in the order to mix things together but didn’t get the separation. Any idea why it didn’t separate?
Mellissa Sevigny says
Not really sure, I didn’t get as much separation on the second one as the first one either. Could depend on the mixing or the amount of air in the egg whites. If I figure it out I’ll post it in the notes!
Madeleine says
I love this. It is one of my favourites. It reminds me of lemon delicious even though its different to that – something about the lemon creaminess and the very flight crust that forms…
In New Zealand our stevia/erythritol blend (we do not have a huge range of sweeteners) is very sweet so I find half a cup is enough, more and it is just too sweet.
We have made this about half a dozen times already, it is my breakfast, my afternoon tea, my dessert… :)
Stephanie says
I am loving this and thank you for your notes on textures. I am a true lemon dessert fan. My MIL however, loves orange creamsicles. Do you think using orange would mimic that flavor profile? Or how about banana extract for another idea? (I have all these extracts, ha, and now ‘m off to go check out your lemon sour cream muffins!)
Mellissa Sevigny says
I definitely think you could adjust the flavor of these with different extracts and/or zests! I’m going to start experimenting too but if you hit on a good combo on your own please let us know!
Dawn King says
Could I do this with lime juice for a faux key lime flavor?
Mellissa Sevigny says
I don’t see why not!
Kelli says
I have powdered Lakanto (monkfruit) Which is twice as sweet as sugar. Should I use half the amount of sweetener? I looked up erythritol and it seems to be less sweet. I’m so bad at math, lol. Can you help?
Mellissa Sevigny says
If you use the monk fruit and cut it in half, I worry about changing the texture of the recipe since the erythritol bulks it up some. If you try it let us know how it turns out – not sure what the amount would be as I’ve never used the powdered Lakanto.
Frances G. Aboud says
I use the Classic Monk fruit Sweetener with Erythritol from Lakanto. It is a one to one sugar replacement. The ups code is 8 43076 00004 4. Since Monk Fruit is a super concentrated ingredient, I recommend that Kelli re-check the ingredient list under the Nutrition Facts on the reverse side of the package of her sweentener. On my package the first ingredient is Erythritol followed by the Monk Fruit. I do not believe that the company Lakanto sells a product that is pure Monk Fruit only. They do have a Golden version which is a brown sugar substitute and a powdered version also which may be made at home by placing the Classic in a food processor. This is a wonderful product that can be bought at the Lakanto web site if it is not available in your area locally. Also Erythritol is used as part of the ingredients in several of the different brands of artificial sweeteners as Erythritol itself is not very sweet and it has no after taste which helps to lower the after taste in other products it is paired with. Hope this helps.
Strawberry Girl says
Has anyone tried this recipe with coconut flour only, no nuts?
Allison says
I jusjust made it yesterday with coconut flour. I added an additional egg and used a total of half a cup coconut flour. It turned out fantastic, but the bottom is really wet. I might try it without the additional egg next time.
Allison says
Update, although the bottom is still very moist it’s no longer wet. It tastes fantastic.