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Keto/Low Carb Sour Cream Coffee Cake

Updated: Oct 14, 2022

It all started with zucchini bread, I found the perfect ratio of unflavored whey protein isolate and coconut flour to get the lightest keto loaf imaginable. So I've been experimenting with it ever since and it's mostly been working!!! It made my first trial of this coffee cake edible!!! woohoo a victory unlike many for someone who has been experimenting and creating some very inedible 1st. tries. Just a little tweaking and I got a keto coffee cake that felt and looked like a regular sweet breakfast bread texture. Just in time for Christmas breakfast!

The sweetener I used was classic granular monkfruit/erythritol but any keto sweetener will work in bread. Just remember certain sweeteners are sweeter than sugar, specifically stevia and splenda. I don't recommend using all Allulose for baked goods that have to cook for longer than 45 minutes because it browns too much after 45 minutes in the oven and this sour cream coffee cake takes 50-55 minutes to bake.

The "flour" mix I use is what I found to make the softest keto baked goods. So happy to have found this ratio, so far everything I have tried it in has come out so soft and light with no graininess. I don't know of many replacements for these ingredients except you can use different flavors of whey protein isolate. Just remember that many of them will add carbs and more sweetness, so you may have to adjust for that. If you really want to use almond flour, the ratio is 3-4x the amount coconut flour for almond flour. So 30g of coconut flour you will need 90-120g almond flour, I would start with less and gradually add more until you get the consistency of a batter.

The crumble topping is pretty simple and 0 Net carbs, crispy and crunchy. The perfect topping for the slightly sweet, moist, soft cake. I tried several variations of the crumble for my strawberry rhubarb crisp and many things turned out well, even using coconut flour but that added too many carbs on top of the rhubarb and strawberries. So I'm sure there are many different things you can use to make it, just make sure you have a crumbly texture after adding the butter. But it won't be zero carb crumble anymore. You can also add any spices or extracts you would like, I just kept it simple with ground cinnamon. Same goes for the extract in the batter, I used vanilla but I tried it with maple and it was yummy, I bet almond would be good too.

For the cinnamon sugar layer I used lakanto golden monkfruit/erythritol blend mixed with cinnamon. You can use any brown sugar substitute you would like, it might make the middle more moist though. I just started experimenting with swerve brown sugar substitute and it's definitely more moist of an ingredient than the golden monkfruit is.

I used an 8x8 baking dish because that is all I own but it would work well in a 9x9, it almost spills out of the 8x8. The 9x9 may take a little less time to cook maybe 45-50 minutes. It would probably also work in a bunt pan, you could put the crumble in the bottom first then the batter and cinnamon sugar layers. I would only bake it 40-45 minutes though. You just want it no longer mushy feeling in the middle but be soft and bounce back when pressed.

Amazon Affiliate Links for products I use and items I regularly buy on Amazon: If you want to support my channel in a small way by buying ingredients you already use or need by clicking my links, I'd really appreciate it. I get a few cents per purchase which could really help with all the testing I do, to make these recipes the best possible.

Reynolds Kitchens Cookie Baking Sheets, Pre-Cut Parchment Paper, White 25 Sheets (Pack of 4), 100 Total Sheets - One Pack -

Anchor Hocking Baking and Storage Set -

Mini Offset Spatula -

Granular monkfruit-

Lakanto golden monkfruit sweetener-

Isopure Unflavored whey protein isolate-

Coconut Flour -

(As an Amazon Associate I earn from qualifying purchases)

Keto Sour Cream Coffee Cake Recipe


4 Eggs (room temp)

144 g Classic Monkfruit/erythritol Sweetener (3/4 Cup)

112 g Salted Butter (8 Tbs.)

224 g Sour Cream (1 Cup)

80 g Unflavored Whey Protein Isolate (Approximately 3/4 Cup)

30 g Coconut Flour (1/4 Cup)

1 Tbs. Baking Powder

1 tsp. Xanthan Gum

1 Tbs. Vanilla Extract

Cinnamon sugar layer-

24 g Golden Monkfruit/Erythritol (2 Tbs.)

1 tsp. Ground Cinnamon


30 g Unflavored Whey Protein Isolate (1 Very packed scoop)

30 g Oat Fiber (1/4 Cup + 2 Tbs.)

72 g Golden Monkfruit Sweetener (6 Tbs.)

1/2 tsp. Ground Cinnamon

112 g Butter (1/2 Cup)


  1. Pull out eggs and soak in warm water, weight out the alternative sweetener into a stand mixer bowl with a whip attachment or into a medium size mixing bowl and preheat oven to 325 degrees

  2. Once eggs are warm, start beating the eggs with the sweetener, depending on how warm the eggs are and how high of a speed you use, it could take 5-10 minutes, you want it triple in volume, pale and thick with little to no sugar crystals

  3. While that is whipping measure, sift and whisk together dry ingredients for the batter, melt butter and measure sour cream and set aside

  4. Make the crumble by measuring, sifting and whisking dry ingredients together then adding melted butter and mixing to combine, set aside, line an 8x8 or 9x9 square baking dish along the bottom and 2 sides with avocado oil spray and parchment paper

  5. Once the eggs and sweetener are light and fluffy, stream in melted butter while the mixer is on low, add in the vanilla extract, then add the sour cream on low, speed up to mix well, scraping down a few times between additions of each ingredient

  6. Once everything is harmonious, turn off the mixer and add in the dry ingredients, mix on a slow speed until most is incorporated then scrap down the bowl and mix until combined

  7. Take the bowl off the mixer and stir with a spatula to ensure everything is combined then layer half the batter into the bottom of the greased baking dish, spread out evenly around all sides

  8. Sprinkle the cinnamon and sugar over the entire layer evenly, then slowly pour the rest of the batter over the cinnamon and sugar trying not to disturb the bottom later, once no cinnamon sugar is showing, spread out the batter evenly with an offset spatula

  9. Top with all the crumble, getting it all the way to the edge and spread evenly

  10. Bake at 325 for 50-55 minutes turning half way through to ensure it bakes evenly, when it's done it should be soft in the middle but no longer feel mushy, let cool completely before slicing

Macros: 1/12

242 calories

21 g Fat

5.3 g Total Carbs

3.5 g Fiber

1.8 g Net Carbs

11 g Protein

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Sep 28, 2022

It’s good - but what did I do wrong? My crunch ended up towards the bottom. I put it on the top as directed in the recipe. I’ve made this twice and both times it sunk! Any ideas?


Leanne Knebel
Sep 16, 2022

Looks awesome just curious why you don’t beat the sweetener with room temperature butter and then add the eggs like a traditional coffee cake? Would whipping the butter with the sweetener not help to reduce the grainy sugars and then the eggs add more volume? Just curious why you used melted better instead after the eggs and sweetener?

Keto Upgrade
Keto Upgrade
Sep 16, 2022
Replying to

I think just warming everything up with the melted butter helps to get rid of the graininess. You can probably do it the other way too. I don't remember exactly how I got to this way of doing it, it probably started with another recipe and naturally progressed from there. I have a lot of recipes, lol.


May 21, 2022

I wish your website had a PRINT option for your recipes.

Alice Koch
Alice Koch
Aug 24, 2023
Replying to

You can use an app called Paprika to download the recipe from the website. Then you can email it to yourself and print it. Or I just leave it on the cloud and have a virtual cookbook.


Dec 25, 2021

This coffee cake looks delicious! I am wondering if I could substitute whey protein for the isolate?

Keto Upgrade
Keto Upgrade
Dec 25, 2021
Replying to

Thank you!! So I'm guessing you mean whey protein concentrate. I just looked up the difference between the 2 and they seem pretty similar, concentrate has more carbs, less protein and more fat so you will have to adjust the macros. But it should be fine to replace the isolate, I can't guarantee the same outcome for sure though. Happy keto baking!


Katie Binkley
Dec 25, 2021

We made this Christmas Eve day thinking we would wait till Christmas morning. We cut it at 1 am and again this morning. What a delicious recipe to try. We highly recommend making this, it’s the first time we could enjoy coffee cake with our coffee for a very long time.

Keto Upgrade
Keto Upgrade
Dec 25, 2021
Replying to

Yay!! So happy you loved it!

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