Fluffy Sugar Free Yogurt Cake

If you popped by my kitchen last Sunday, you would have found me whisking while chatting on the phone and shooing the cat off the counter, which is exactly how this Fluffy Sugar Free Yogurt Cake usually happens. I started making it when my aunt hinted that her old yogurt loaf could be even lighter, and now it is the cake I pull out when friends come over and I want something soft and cozy, but not cloying. It reminds me of picnic cakes from when I was little, just less sweet, more cloud. Also, my wooden spoons clack in the drawer like a tiny drumline and it always makes me grin for no reason at all.

Why I keep making this one

I make this when I want dessert that does not send me into a sugar nap. My family goes a bit bonkers for it because it is fluffy and gently tangy, and it takes toppings like a champ. It is also a no faff batter most days, unless I separate the eggs for that extra lift, which I do when I am feeling fancy. And I used to struggle with sugar free baking because some cakes came out gritty or oddly cool on the tongue, but this one behaves. Mostly. If your sweetener is super cold, the batter can look a bit stiff, but it bakes up lovely.

What you will need and a few swaps

1 cup full fat Greek yogurt 250 g, room temp if you remember. Regular yogurt works too, just drain it a touch if it is very loose.
3 large eggs, separated if you want extra fluff, whole if you want minimal washing up.
3 quarters cup granulated erythritol or a monk fruit blend 150 g. If you use a different sweetener, peek at this sweetener conversion chart I reference.
1 and 1 quarter cups all purpose flour 160 g. I sometimes swap 1 quarter cup for almond flour for tenderness.
2 teaspoons baking powder, fresh.
1 quarter teaspoon fine salt.
1 third cup light olive oil or melted unsalted butter 75 ml. I have used avocado oil in a pinch and it was grand.
2 teaspoons vanilla extract.
Finely grated zest of 1 lemon or orange, optional but gorgeous.
A handful of berries for the top, optional. My grandmother always insisted on a specific brand of blueberries, but honestly any you like are fine.

On sweeteners, I avoid pure stevia here, it can get a little bitter. Erythritol monk fruit blends tend to play nicest with this batter.

Let us bake it

Heat the oven to 350 F 175 C. Grease an 8 inch round pan and line the base with parchment. If you are a parchment circle skeptic, this King Arthur guide is genuinely helpful.
In a bowl, whisk together flour, baking powder, and salt. Just a quick stir to blend, no need to overthink it.
In a separate large bowl, whisk the yogurt, sweetener, vanilla, and zest until smooth. This is where I usually sneak a taste.
Add the egg yolks to the yogurt bowl and whisk until it looks glossy. Stream in the oil while whisking. I used to add the oil first, but actually, I find it works better if it goes in after the yolks.
Tip the dry ingredients into the wet and stir gently until you see only a few streaks. It is okay if the batter looks a touch thick. Do not worry if it looks a bit weird at this stage, it always does.
If you separated the eggs, beat the whites to soft peaks with a pinch of salt. Fold them into the batter in three additions, keeping as much air as you can. If you did not separate them, no problem, just make sure the batter looks smooth and friendly.
Scrape the batter into the pan, smooth the top, and dot with a handful of berries if using. Tap the pan once on the counter to settle things.
Bake for 35 to 45 minutes until the top is lightly golden and a skewer comes out mostly clean. A few moist crumbs are perfect. If it is browning fast, tent loosely with foil.
Cool 10 minutes in the pan, then run a thin knife around the edge and turn it out. Let it cool fully on a rack. I know it is tempting, but if you slice while it is hot, it can seem a bit damp.

On second thought, if you love warm cake, go for it. I am not the boss of your fork. Just know the texture sets as it cools and gets fluffier.

A couple notes from my messy notebook

Room temp ingredients make the batter relax. When the yogurt is cold, I warm it slightly by setting the tub in a bowl of warm water for a few minutes.
Greek vs regular yogurt: Greek gives a tighter crumb and more protein. Regular gives a softer, slightly looser crumb. If you are curious about the differences, this Serious Eats explainer is great.
If your sweetener crystallizes on top as it cools, a light brush with warm water smooths it out. Learned that after a slightly sparkly cake, which was cute but odd.
I think this tastes better the next day after a night in the fridge, it gets that settled flavor I love.

Variations I have tried

Lemon blueberry: add extra zest and press a handful of blueberries on top before baking. Simple and cheerful.
Cocoa ripple: whisk 2 tablespoons unsweetened cocoa with 1 tablespoon warm water and swirl through half the batter. It bakes up like a mellow marble.
Almond vibe: swap a quarter cup of the flour for almond flour and add a few drops of almond extract. Nice with sliced pears.
Did not love: I once used only liquid stevia and skipped all erythritol, and the cake turned rubbery and slightly bitter. Maybe my drops were too enthusiastic, but I would not do that again.

Gear I use, and what to do if you do not have it

8 inch round pan or a 9 by 5 loaf pan. The round looks prettier, but the loaf works when I am packing slices for lunch.
Hand mixer for the egg whites. I call it essential, although a whisk and a good playlist will get you there if you are patient.
Rubber spatula for folding. If you only have a wooden spoon, it is fine, go gently and it will still be fluffy.
Parchment for the base. If you are out, grease the pan well and dust with a little flour.

How I store it

Let the cake cool completely, then keep it covered in the fridge for up to 4 days. It firms a touch and slices like a dream. You can also freeze slices for a month, well wrapped, then thaw on the counter. Though honestly, in my house it never lasts more than a day.

Serving ideas we love

We do a dollop of unsweetened whipped cream and a tumble of strawberries, or a drizzle of warm peanut butter for a sort of breakfast cake situation. For company, I dust with a little powdered erythritol so it looks snow kissed. On rainy afternoons, I serve it with hot tea and a cheeky slice of cheddar because I grew up that way and it makes sense in my brain.

Pro tips I learned the hard way

I once tried rushing the cooling and sliced too soon, regretted it because the crumb squished. Give it those 10 minutes in the pan.
I forgot the salt one time, and the flavor was oddly flat. A pinch really matters here.
Another day I beat the egg whites to stiff dry peaks and they would not fold in. Soft peaks are the sweet spot.
Do not overbake waiting for a squeaky clean skewer. If you do, it dries out on day two and loses its charm.

You asked, I answered

Can I make this gluten free
Probably. Use a good cup for cup gluten free flour blend and add a scant quarter teaspoon xanthan if your blend does not include it. Texture stays light.

Can I use coconut flour
I tried and it drinks up moisture like a sponge. The cake turned dense. I would not recommend it here.

What if I only have regular yogurt
Totally fine. If it is very runny, spoon it into a sieve for 15 minutes to drain a little. Or just add a tablespoon more flour and carry on.

Is the sweetener swap one to one with sugar
Most erythritol blends are close, but check your brand. When in doubt, peek at the conversion chart I linked above. If your mix is extra sweet, start with a bit less and taste the batter.

Do I have to separate the eggs
Nope. It makes it extra airy, but the cake is still fluffy without that step. On busy nights I just whisk whole eggs and it is grand.

Why is my cake a little sunken in the middle
Usually underbaked or the oven ran a bit cool. Next time bake a few minutes longer. Also, do not fling the door open too early, ask me how I know.

One tiny digression

Every time I zest a lemon for this, the kitchen smells like a bright morning after rain, and I remember my neighbor teaching me how to grow basil on the sill. Which is completely unrelated, except I sometimes chop that basil over strawberries for the top and it is quietly brilliant.

Quick recap for distracted bakers

Whisk wet, fold in dry, whip whites if you are up for it, bake until golden. Let it cool in it's pan for 10 minutes, then free the edges and flip. Eat warm if you must, but it really hits its stride after it cools. Pour it form the bowl with confidence and you are golden.