This Keto Blueberry Cake is the kind of dessert you can make on a weeknight and still feel good about. It’s light, tender, and packed with juicy blueberries in every bite, but without the sugar crash. If you’re following a low-carb or keto lifestyle, this cake gives you a sweet finish that actually fits your goals.
Even non-keto folks will enjoy it, which makes it perfect for family gatherings or weekend brunch. Simple ingredients, quick prep, and a lovely lemon-kissed flavor—what’s not to love?
Ingredients
Method
- Preheat and prep: Heat your oven to 350°F (175°C). Line an 8-inch round cake pan or square pan with parchment and lightly grease the sides.
- Mix dry ingredients: In a bowl, whisk 2 cups almond flour, 2 tablespoons coconut flour, 2 teaspoons baking powder, and 1/4 teaspoon sea salt until well combined.
- Whisk the wet: In a separate bowl, whisk 3/4 cup granulated erythritol or allulose, 1/2 cup melted butter (cooled) or coconut oil, 3 large eggs, 1/2 cup unsweetened almond milk, 1 teaspoon vanilla, 1 tablespoon lemon zest, and 1 tablespoon lemon juice.
- Combine: Pour the wet mixture into the dry and stir until just smooth. The batter will be thicker than traditional cake batter; that’s normal with almond flour.
- Fold in blueberries: Gently fold in 3/4 cup blueberries. If using frozen, do not thaw; toss them with a teaspoon of almond flour first to reduce bleeding.
- Fill the pan: Spread the batter evenly and smooth the top with a spatula. If you like, dot a few extra blueberries on top.
- Bake: Bake 28–35 minutes, or until the top is golden and a toothpick comes out mostly clean with a few moist crumbs. Do not overbake.
- Cool: Let the cake cool in the pan for 10 minutes, then lift it out using the parchment and transfer to a rack to cool completely.
- Finish and serve: Dust with powdered sweetener and serve as-is or with lightly sweetened whipped cream. A few extra lemon zest curls are lovely.
What Makes This Recipe So Good
- Low in carbs, big on flavor: Almond and coconut flour create a moist crumb without the heavy carb count.
- Balanced sweetness: Uses keto-friendly sweeteners that taste clean and don’t leave a strange aftertaste.
- Blueberries that shine: A small amount goes a long way, adding bursts of sweetness and color.
- Easy to make: One bowl for the dry, one for the wet, and you’re on your way to a golden, tender cake.
- Great for brunch or dessert: Lovely plain, dusted with powdered sweetener, or topped with whipped cream.
Shopping List
- Almond flour (super-fine)
- Coconut flour
- Granulated erythritol or allulose (or a blend)
- Baking powder
- Sea salt
- Unsalted butter (melted and cooled) or coconut oil
- Large eggs
- Unsweetened almond milk (or another low-carb milk)
- Vanilla extract
- Lemon zest and juice
- Fresh or frozen blueberries
- Powdered erythritol or allulose for dusting (optional)
- Heavy cream and a touch of sweetener for whipped cream (optional)
How to Make It
- Preheat and prep: Heat your oven to 350°F (175°C). Line an 8-inch round cake pan or square pan with parchment and lightly grease the sides.
- Mix dry ingredients: In a bowl, whisk 2 cups almond flour, 2 tablespoons coconut flour, 2 teaspoons baking powder, and 1/4 teaspoon sea salt until well combined.
- Whisk the wet: In a separate bowl, whisk 3/4 cup granulated erythritol or allulose, 1/2 cup melted butter (cooled) or coconut oil, 3 large eggs, 1/2 cup unsweetened almond milk, 1 teaspoon vanilla, 1 tablespoon lemon zest, and 1 tablespoon lemon juice.
- Combine: Pour the wet mixture into the dry and stir until just smooth.
The batter will be thicker than traditional cake batter; that’s normal with almond flour.
- Fold in blueberries: Gently fold in 3/4 cup blueberries. If using frozen, do not thaw; toss them with a teaspoon of almond flour first to reduce bleeding.
- Fill the pan: Spread the batter evenly and smooth the top with a spatula. If you like, dot a few extra blueberries on top.
- Bake: Bake 28–35 minutes, or until the top is golden and a toothpick comes out mostly clean with a few moist crumbs.
Do not overbake.
- Cool: Let the cake cool in the pan for 10 minutes, then lift it out using the parchment and transfer to a rack to cool completely.
- Finish and serve: Dust with powdered sweetener and serve as-is or with lightly sweetened whipped cream. A few extra lemon zest curls are lovely.
Storage Instructions
- Room temperature: Keep covered for up to 24 hours if your kitchen is cool.
- Refrigerator: Store in an airtight container for 4–5 days. The texture stays moist and tender.
- Freezer: Slice, wrap each piece, and freeze for up to 2 months.
Thaw in the fridge overnight or at room temperature for 30 minutes.
- Reheat: Warm a slice in the microwave for 10–15 seconds, or in a low oven for 5 minutes.
Health Benefits
- Lower in carbs: Almond and coconut flours keep net carbs down compared to wheat-based cakes.
- Higher in fiber and healthy fats: These flours provide satiety and help keep blood sugar more stable.
- Blueberries bring antioxidants: A modest amount adds vitamin C and polyphenols without pushing carbs too high.
- Customizable sweeteners: Erythritol and allulose have little to no effect on blood sugar for most people.
What Not to Do
- Don’t swap almond flour for coconut flour one-to-one: Coconut flour is far more absorbent and needs more liquid and eggs.
- Don’t overmix: Stir just until combined to avoid a dense, rubbery crumb.
- Don’t overbake: Keto cakes can dry out quickly. Pull it when the center is set and a toothpick shows moist crumbs.
- Don’t use sugar-heavy add-ins: Regular chocolate chips, sweetened dried fruit, or glazes will spike carbs.
- Don’t skip cooling time: The crumb sets as it cools, making cleaner slices and better texture.
Recipe Variations
- Lemon Blueberry Loaf: Bake in a loaf pan at 325°F (165°C) for 45–60 minutes. Add an extra teaspoon of lemon zest.
- Blueberry Almond Crumble Cake: Sprinkle the top with a quick keto crumble made from almond flour, sweetener, and butter before baking.
- Cream Cheese Swirl: Dollop a simple mix of softened cream cheese, sweetener, vanilla, and a splash of almond milk on top and swirl with a knife.
- Lavender Twist: Add a pinch of culinary lavender with the dry ingredients for a gentle floral note.
- Nut-Free Version: Use a finely ground sunflower seed flour in place of almond flour.
Expect a slightly stronger flavor and a greenish tint from sunflower chlorophyll reacting with baking powder—totally safe.
FAQ
Can I use only coconut flour?
Coconut flour alone will make the cake too dry and dense unless you dramatically adjust liquids and eggs. A blend with almond flour gives the best texture and flavor.
Which sweetener is best?
Allulose gives a softer crumb and less cooling effect, while erythritol offers more structure and sweetness by volume. A blend often tastes most balanced.
Start with the amounts listed and adjust to your preference.
Can I use frozen blueberries?
Yes. Add them straight from the freezer and toss with a little almond flour to limit color bleed. You may need an extra 2–3 minutes of bake time.
How many carbs per slice?
Exact macros depend on brands and portion size, but for an 8-slice cake, expect roughly 4–6g net carbs per slice using almond flour, a keto sweetener, and 3/4 cup blueberries.
Calculate with your specific ingredients for accuracy.
Why did my cake sink in the middle?
Common causes include underbaking, opening the oven too early, or too much liquid. Bake until the center is set and springs back lightly, and avoid peeking for the first 20 minutes.
Can I make it dairy-free?
Yes. Use coconut oil instead of butter and a non-dairy milk like almond or coconut milk.
The texture will remain tender, with a subtle coconut note.
How do I prevent a gritty texture?
Use super-fine almond flour, not almond meal. Let the batter rest for 5 minutes before baking so the flours hydrate, which helps the crumb feel smoother.
In Conclusion
This Keto Blueberry Cake checks all the boxes: simple, satisfying, and low in carbs without sacrificing flavor. The lemon and vanilla make the blueberries pop, and the almond-coconut blend keeps the crumb moist and light. Keep it on hand for brunch, a midday treat, or a sweet finish after dinner. It’s a cozy classic, reworked for a low-carb lifestyle and made to share.
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