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

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.

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:





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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!
Ingredients
Crumb Topping
- 1 1/2 cups (6.75 oz, 189g) cake flour
- 2/3 cup (6 oz, 168g) light brown sugar
- pinch of salt
- 2 teaspoons cinnamon
- Zest of 1/2 lemon
- 1 stick (4 oz, 112g) softened unsalted butter, cut into 1" pieces
Cake Batter
- 1 large egg plus 1 yolk
- 1/2 cup (4 oz, 120ml) buttermilk, divided
- 1 1/2 cups (6.75 oz, 189g) cake flour
- 3/4 cup (6 oz, 168g) granulated sugar
- 1 1/2 teaspoons baking powder
- 1/4 teaspoon salt
- zest of 1/2 lemon
- 1 stick (4 oz, 112g) butter, softened and cut into 1" pieces
- 1 pint fresh (or frozen) blueberries
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.
Batter
- Combine the egg, yolk and 1/4 cup of the buttermilk in a small bowl and set aside.
- 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.
- 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.
- 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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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.
Christie J
Sunday 28th of June 2020
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!
Eileen Gray
Sunday 28th of June 2020
The time listed in the recipe is always just a guideline. Go by how the cake looks and if a toothpick comes out clean.
grace costa
Monday 24th of February 2020
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.
grace costa
Wednesday 19th of February 2020
Hi, can I use a 9 inch round springform pan?
Eileen Gray
Wednesday 19th of February 2020
Yes, that should work just fine.
Monali
Thursday 30th of January 2020
Hi Eileen,
Thank you for the suggestion. I have two 9 inch round pans. Would you advise to use that?
Eileen Gray
Thursday 30th of January 2020
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.
Monali
Thursday 30th of January 2020
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
Eileen Gray
Thursday 30th of January 2020
Hi Monali, For 18-20 people I would suggest you double the recipe and bake in two 10" round pans if you have them. Use one batch of Cream Cheese Frosting to fill and ice the cake.