Blueberry Crumb Cake – Blueberry Buttermilk Coffee Cake

Blueberry Crumb Cake! Soft blueberry buttermilk coffee cake crowned with brown sugar crumb topping. It’s all about that perfect crumb topping!

a Blueberry Crumb Cake on a cake stand

As I’ve mentioned in previous posts, after years of thinking about, baking, decorating and delivering cakes for a living about the last thing I want to bake and eat at home is cake.

But crumb cake is another thing all together. Even though I’m a little sick of cake, I love the combination of a light and soft buttermilk cake under a chunky topping of  brown sugar  and cinnamon crumbs.

Let’s face it, it’s all about the crumb topping! Folding fresh blueberries into the batter and layering more berries into the crumb topping takes this treat into another league altogether.

This is a cake even I look forward to eating. It’s great for dessert or with a cup of tea, but you could also have it for breakfast or brunch on the weekend.

a blueberry patch
This is the blueberry patch at the farm. The netting keeps the birds out.

Tips for making a great Blueberry Buttermilk Coffee Cake:

  • For this recipe I knew I wanted to use a buttermilk cake for the base layer. Buttermilk is a fantastic baking ingredient. Not only does it add moisture and a nice tangy flavor to a recipe, buttermilk is acidic so it tenderizes the cake crumb.
  • You’ll notice that there is no baking soda in the recipe, only baking powder. Baking soda is on the base side of the pH scale, so it’s used with acidic ingredients to balance the pH of a batter. I purposely did not use baking soda because I wanted to keep the batter slightly acidic. This is one of the softest cakes you’ll ever taste. It absolutely melts in your mouth.
  • The key to a good crumb layer is to mix softened butter into the dry ingredients until it looks exactly like wet sand. When you grab a handful of the mixture it will clump together. By adding the crumb topping in chunks you’ll get nice big crumbs in each mouthful of cake.
  • I used fresh blueberries for this cake, but you could certainly use frozen berries. Don’t defrost them first. You should fold them into the batter while they’re still frozen so they don’t break down and turn the entire cake green.

Scroll through the step-by-step photos to see how to make Blueberry Crumb Cake from scratch:

a bowl of crumb topping
The crumb topping should look like sand and form a clump when squeezed
cake batter with blueberries in a square pan
Dot blueberries on top of the batter before adding the crumb topping
a hand sprinkling crumb topping onto a cake
Break the large clumps of topping into smaller clumps from pea sized to the size of a marblea Blueberry Crumb Cake
a slice of blueberry buttermilk coffee cake

If you love this recipe as much as I do, please consider leaving a 5-star review.

a Blueberry Crumb Cake on a cake stand
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4.52 from 50 reviews

Blueberry Crumb Cake

I love the combination of a very light and soft cake under a chunky topping of  brown sugar  and cinnamon crumbs. Let’s face it, it’s all about the crumb topping and the blueberries!
Prep Time30 minutes
Bake Time1 hour
Total Time1 hour 30 minutes
12 portions
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Ingredients

Crumb Topping

  • 6 3/4 oz Cake flour (1 1/2 cups, see note)
  • 6 oz brown sugar (2/3 cup)
  • 1/4 teaspoon table salt
  • 2 teaspoons cinnamon
  • 1/2 teaspoon lemon zest
  • 4 oz unsalted butter (room temperature)

Cake Batter

  • 1 each large eggs
  • 1 each egg yolks
  • 4 oz buttermilk (1/2 cup, divided)
  • 6 3/4 oz Cake flour (1 1/2 cups)
  • 6 oz granulated sugar (3/4 cup)
  • 1 1/2 teaspoons baking powder
  • 1/4 teaspoon salt
  • 1 teaspoon lemon zest
  • 4 oz unsalted butter (room temperature)
  • 10 oz blueberries (2 cups)

Instructions

  • Preheat the oven to 350°F. Butter and flour an 9″ square cake pan. Cut an 8″x16″ piece of parchment paper and line the pan in one direction, leaving a short overhand on each side. Butter and flour the parchment.

Crumb Topping

  • Combine the flour, brown sugar, salt, cinnamon and zest. Mix on low speed until completely combined. With the mixer running, add the butter and continue to mix until the topping looks like sand. Remove from the mixer and transfer to a small bowl by squeezing handfuls to create large clumps. Set aside while you mix the batter.
    6 3/4 oz Cake flour, 6 oz brown sugar, 1/4 teaspoon table salt, 2 teaspoons cinnamon, 1/2 teaspoon lemon zest, 4 oz unsalted butter

Batter

  • Combine the egg, yolk and 1/4 cup of the buttermilk in a small bowl and set aside.
    1 each large eggs, 1 each egg yolks, 4 oz buttermilk
  • Sift together the flour, sugar, baking powder and salt. add the zest. With the mixer running on low speed, add the butter and the remaining 1/4 cup of buttermilk. Mix until completely combined. Scrape the bowl and beater. Mix on medium speed for 2-3 minutes to lighten the batter.
    6 3/4 oz Cake flour, 6 oz granulated sugar, 1 1/2 teaspoons baking powder, 1/4 teaspoon salt, 1 teaspoon lemon zest, 4 oz unsalted butter
  • Scrape the bowl and add the egg mixture in two batches, scraping between additions. By hand, fold about 2/3 of the blueberries into the batter. Spread the batter into the prepared pan.
    10 oz blueberries
  • Sprinkle 1/2 the remaining blueberries over the top of the batter. Sprinkle 1/2 the crumb topping over the batter, breaking the topping into pea to marble sized clumps. Sprinkle the rest of blueberries and then the remaining crumb topping.
  • Bake until a toothpick inserted in the center comes out clean, about 40-45 minutes. Cool at least 30 minutes in the pan. Use the parchment to carefully lift the cake out of the pan.
  • Cool completely on a wire rack

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Notes

If measuring the flour by volume use the “dip & sweep” method. That is, dip the measuring cup into the flour bin, overfill it, then sweep away the excess.

Nutrition

Serving: 1slice | Calories: 380kcal | Carbohydrates: 56g | Protein: 5g | Fat: 16g | Saturated Fat: 10g | Polyunsaturated Fat: 1g | Monounsaturated Fat: 4g | Trans Fat: 1g | Cholesterol: 43mg | Sodium: 167mg | Potassium: 89mg | Fiber: 2g | Sugar: 31g | Vitamin A: 504IU | Vitamin C: 3mg | Calcium: 67mg | Iron: 1mg
Have you tried this recipe?Mention @eileen.bakingsense or tag #bakingsense!

Since you love coffee cake, try these other fabulous recipes: Rhubarb Crumb Cake, Peach & Pecan Coffee Cake, Banana Coffee Cake, Pumpkin Coffee Cake, Sourdough Coffee Cake and Sourdough Crumb Cake.

And here are some more blueberry recipes: Blueberry Cheesecake Tart, Blueberry Preserves, Lemon Blueberry Macarons, Blueberry Hand Pies, Blueberry & Cherry Shortcakes and Blueberry Crumb Bars..

30 Comments

    1. I haven’t tried it but I think it would probably work. The problem is, the crumbs will be on the “bottom” of the cake once you turn it out of the pan.

  1. Making this a 2nd or 3rd time now who’s counting all I know is I get to the last slice an making another one before it runs out that good this recipe is!!! Thanks for sharing an look forward to many more to make my list of guilt pleasures 🙂

  2. I am baking this right now…it smells so good! But – it’s been in the oven for 60 minutes now, at 350°, in a metal 9″ square pan and it is still raw in the middle.
    My oven is new and I haven’t had this problem before so it is not the oven. What could be going on ?
    Thanks!

    1. The time listed in the recipe is always just a guideline. Go by how the cake looks and if a toothpick comes out clean.

  3. I baked this over the weekend … I had no lemons so I added 1/4 tea lemon extract and a tea of vanilla. was delicious and everyone loved it. also took longer than 45 minutes to bake. I used a 9 inch square pan but took about 7 minutes long.to bake. will definitely bake this again.

    1. You can use 9″ pans, but a double batch would probably be a little too large. Also, depending on the portion size, a 9″ cake may not feed 18-20p.

  4. Hi Eileen,
    Hope you are doing great!!
    I just want to bake the blueberry cake (without the crumble on top) and do cream cheese frosting as layer cake. I want to use this recipe for the blueberry cake. Do you recommend to do that?
    Also, I want to make the cake for serving of 18-20 people..can you please suggest me the quantity of cake flour that I should take?
    Any other suggestions that I need to do.

    Thanks
    Monali

    1. Hi Naleema? Are you based in the US? Cake flour is sold here in the US and is flour made with soft wheat with a lower protein content. It’s good for making cakes, biscuits and other baked good with a soft crumb.

  5. wow. you were right. the cake literally just melts in your mouth. it is so light and fluffy and the flavor with the blueberries is delicious.
    I have tried NY crumb cakes twice before (two different recipes) and both failed! the crumb always sank to the bottom. :0(
    this one did not. it was perfect in every respect.

    thank you!!

  6. I guess you can’t turn off the top element. If you could that would certainly be better. If you can’t turn off the top element I would try a slightly lower temperature. Cover the pan with aluminum foil with the shiny side up to try and deflect some of the heat away from the top of the cake. If there is more than one shelf you might even put a sheet pan on the shelf above the cake to block the heat from the upper element. Good luck.

    1. Oh, it looks like there is a way to set it to just the bottom or just the top element. I will try with the top one off. Thank you!

  7. Hi Ceeny. I’ve never actually owned or baked in a toaster oven. Is the heat source at the top or bottom of the oven? If it’s coming from the top I think baking a cake will be a challenge.

    1. It has heating elements on both top and bottom. Should I try a higher temperature to start and then lower it?

  8. 5 stars
    Hi Eileen,

    I LOVE this recipe. But I recently moved to Thailand where kitchens don’t have ovens and….help! I have a large toaster oven where I can’t really get an exact temperature and I bake by trial and error. So far I’ve successfully baked some cookies. I’ve also baked some simple cakes/brownies using my 8″ square nonstick dark metal pan. This was my first attempt at baking a cake using sifted cake flour. The cake turned out fine, but the crumb topping just melted into the cake! That’s my favorite part! Then the top started getting too browned before the cake was done, so I turned the temperature down and put foil over the top to keep it from burning. I ended up having to bake it almost twice as long. Do you have any ideas on what I can do? I also have a cupcake pan if that would help (same dark non-stick coating). Also, can I just bake the crumb topping by itself and add it to my other cake for now? It has been quite a challenge learning to bake in a toaster oven. I miss my real oven!

    1. Hi Christelle, I think you could probably bake it in a skillet. Just be aware that a cast iron skillet will bake much hotter so the cake will brown more. You might have to play with the oven temperature based on the material of the skillet. Let me know how it turns out if you try it. Happy Baking!

  9. 5 stars
    I tried making this a few days ago and can’t wait to make it again! It was a little more involved than my normal recipes where everything pretty much gets dumped and mixed into one bowl. But the extra effort was soooo worth it! I actually messed up the recipe by using a whole stick of butter in the batter. So I ended up putting it back into the oven a few times because it was still raw in places. I couldn’t stop nibbling on the cooked parts while waiting for it to finish cooking though, so it wasn’t very pretty in the end (and about half gone too!). The cake was unbelievably moist and was the perfect texture. This is the best crumb cake I’ve ever had! I was hoping it would be similar to the Starbucks coffee cake but this was so much better!

    How do I change out the blueberries for a cinnamon (like coffee cake) version? What are other good variations on it in case I’m out of blueberries? I LOVE this recipe! I also love how you do so much testing and your explanations of techniques and why things do/don’t work. That must be unbelievably time consuming. Thank you so much for sharing your hard work!

    1. Hi Ceeny! Thanks for visiting my blog and for trying the recipe. I’m glad you think it was worth the effort!

      This cake does take kind of long to bake. I used a straight-sided, square 8″ pan. If your pan was a different shape or size it could affect the baking time. Whatever pan you use, the cake batter should come just 1/2 way up the sides of the pan. If you have too much batter just use the extra in a smaller pan or make a few muffins.

      Variations: You could just bake it without the blueberries for a plain crumb cake. You could add a teaspoon or so of cinnamon with the dry ingredients for a cinnamon cake. Do you mean you’d like to have a cinnamon swirl or ripple in the cake? I’d have to try it, but my first thought would be to put 1/2 the batter in the pan, sprinkle a layer of cinnamon sugar over that batter and then put the remaining batter and then the crumb topping in the pan. If you try it let me know how it works. You can also fold in raspberries, cranberries or chunks of fruit (like peach) if you have those on hand instead of blueberries.

      I’m sure in the future I’ll do other versions of crumb cake. I think an apple cinnamon version would be good for fall.

      1. Ah, yes. Maybe it was my pan that affected my baking time. I used a glass 8″ square pan. I think my oven also heats lower than the setting. I haven’t baked many cakes in this oven and I did have another cake that didn’t brown recently. It also had some under-cooked spots in it.

        I have some round heavy metal cake pans, so I will try one of those next time and add 15 degrees to my oven temparature too. I like your cinnamon swirl idea. And apples with it….yum! Maybe fall will have to come sooner for me. 🙂

        1. Not only does the size and shape of the pan affect the way it bakes, but definitely glass will bake differently than metal. Glass is a poor conductor of heat so there’s a good chance that’s why it took longer to bake. The glass pan will take longer to heat up in the oven than a aluminum cake pan would. So of course if the pan takes longer to heat up it takes longer to get the heat to the batter in the pan.

          If it was clear glass you will get a nice brown crust on the bottom because the clear glass allows for the radiant heat to brown the bottom and sides of the cake while it bakes. If you try the recipe in a metal cake pan you may not need to increase the oven temp since it’ll conduct heat better than the glass will anyway.

          This reminds me what a difference the pan you bake in can make. I’ll work on a blog post all about baking pans and how the different materials can affect the baking process. Thanks so much for the feedback and taking the time to comment. Eileen

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