This Blueberry Crumb Coffeecake has everything going for it. It is super easy, beautiful to look at and better to eat. One of the things I most love about this coffeecake is that it is not overwhelmingly sweet.
One mixture makes the crumbs and forms the basis for the batter. This Blueberry Crumb Coffeecake can be mixed and in the oven in 20 minutes.
I love the lemon glaze but if you want to skip this step, just sprinkle it with powdered sugar.
When we made these at the bakery we used wild blueberries because they are smaller. However, they are often hard to find at the stores so regular ones will due just fine. To keep the discoloration to a minimum, use frozen blueberries and keep them frozen until you need to add them. That way they don't juice out in the batter causing the discolortion.
This Blueberry Crumb Coffeecake can be made ahead. Freeze it unwrapped. As soon as it is frozen, wrap it well and keep frozen up to 3 months. Glaze it after it has thawed.
Blueberry Crumb Coffeecake
2 ¼ cups all purpose flour, divided (315 grams or 11 ounces)
1 cup sugar (200 grams or 7 onces)
¾ cup butter , cold (170 grams, 6 ounces or 1 ½ sticks)
1 teaspoon baking soda
1 egg
½ cup buttermilk
9 ounces frozen blueberries (255 grams)
Preheat the oven to 350°F. Spray a 9" cheesecake pan or springform pan and set aside.
Combine 2 cups flour and sugar to the bowl of a mixer.
Cut the butter into small pieces and add it to the bowl. 
Mix on low at first until most of the butter has been cut in. Raise the mixer and continue to mixing until crumbs form. They will be fine and not large crumbs. 
Remove ⅓ of the crumbs (210 grams or about 7 ounces) and set them aside.
Add the remaining ¼ cup flour, baking soda, egg and buttermilk to the remainder of the crumbs in the bowl. Beat on low to bring it together then on medium to smooth it out.
Stir half of the frozen blueberries into the batter. 
Spread it evenly in the pan.
Place the remainder of the blueberries over the top of the batter. 
Sprinkle the crumbs, set aside in the bowl, over the blueberries.
Bake for 50 to 55 minutes until a tester comes out clean. The crumbs will be light in color.
Let cool before removing from the pan.
Lemon Glaze
1 cup powdered sugar (130 grams or 4 ½ ounces)
3 tablespoons lemon juice (plus more if needed)
Combine the powdered sugar and lemon juice in a bowl and stir until smooth and of a consistency to be drizzled.
Place the cake on a rack over waxed or parchment paper for easy clean up. Drizzle one way,
turn the cake and drizzle in the opposite direction. 
Allow the glaze to set before serving.
Note: The cake may be frozen without the glaze. Wrap well after freezing. Thaw and then glaze.
Hi Helen, When you mad this did you use fresh frozen blueberries or packaged blueberries? When I stirred in the blueberries my batter became blue!
Hello Kimberly - In the header of the article, I mention using frozen strawberries and keeping them frozen until using them...."To keep the discoloration to a minimum, use frozen blueberries and keep them frozen until you need to add them. That way they don’t juice out in the batter causing the discolortion." Hope this helps. I used packaged blueberries that were frozen. But it wouldn't make any difference if you froze fresh blueberries - it's the same thing.
Might have been the brand I used, happy to say it came out wonderful not as blue as I thought it was going to be after baking. fantastic recipe, thank-you!
Hi Helen,
I tried to bake it in home but i failed while dividing the flour and adding ingredients.
Not sure why. You put half the crumb mixture in a bowl and left the other half in them mixing bowl? Then you add the baking soda, egg, buttermilk and 1/4 cup flour to the mixing bowl. After mixing half the blueberries are added, then this mixture is spread into the prepared pan. The other half of the blueberries go on top of the batter in the pan, then the reserved crumbs in the bowl go on top of the blueberries.
We made this over and over at the bakery. Hope this helps.
Thanks for the correction, Helen - we were all confused, but it's clear now.
You're welcome. Sometimes I'm too close to the subject to see something I missed even though I read and re-read several times. When so many people had a problem, I knew there was something I missed. Happy to have cleared it up.
Hi Helen - I see what's confusing people. It's because the flour (by itself) is not divided, although it would appear so in the ingredients listing. Only after the sugar is added to (all) the flour, and the butter is cut in and mixed to form a crumb is there a division when 1/3 of the resulting crumb is set aside.
The blueberries are divided. One half the blueberries go into the batter, and 1/2 for later combination with the set-aside crumb to form the topping.
As to the divided flour. I'm thinking 1/4 cut of the flour would get mixed with the frozen blueberries before adding to the batter.
Hi Judy - Boy this recipe has confused a lot of people. Not sure why. No flour is added to the blueberries. Half are added directly to the mixed batter. The second half are put directly on top of the batter with the blueberries in it. The crumbs that were set aside in the bowl are added directly on the top layer of the blueberries.
Hi Judy - no flour is mixed with the blueberries. The recipe tells you to add half the blueberries directly to the mixed batter, spread it into the prepared pan and top with the remaining half of the blueberries. Then you sprinkle the set aside crumb mixture over the blueberries and bake.
why is the flour divided? I assume the larger amount is base but I do not see when the smaller (2nd bowl) amount of flour is added. Could you please explain. Also what other fruits would be good to use in this cake?
Hi Denise - The second part of the crumbs are the ones you sprinkle over the top layer of blueberries. I have add additional words to make the more clear. Sorry for any confusion.
Hi Denise - The smaller amount in the bowl is sprinkled over the top layer of blueberries to make the crumb topping. I imagine any frozen fruit can be added - I have only used blueberries.
Helen is the flour to be divided into two equal parts? This step is not very clear. Also i assume that flour will be added along with baking soda and buttermilk. please clarify.
Hi Manisha - I think you missed this step just above the bowl of crumbs: "Remove 1/3 of the crumbs (210 grams or about 7 ounces) and set them aside." The recipe then tells you to add the rest of the ingredients to the crumbs in the bowl. Hope this helps.
Although there was some confusion the cake turned out fab!!! It is not a very sweet cake which is what I loved about it as it goes so well with my tea.
I flavored the batter with lemon zest and did not use the glaze at all. it was beautiful and nice just like that.
Thank you, Helen, for clarifying the proportion of the flour to be added in the recipe. As I was not sure of the proportion and had already started work on it so I added 50% in two additions. Must say, it is quite a forgiving batter!
Thanx for deep butter cake clarification too. Will retry it and share my update.
HI Manisha - Love lemon and blueberries. I left the drizzle as an option - either way works for me. Thanks for letting me know how it came out.
Helen this looks amazing! Making the cake today will share the result.
I have a query on Deep Butter cake. sorry to post it here but the comment section of this cake is closed. I tried it and got soggy parts throughout the cake and the crumb didn't have crunchy layer/crust. In fact, it was not distinguishable. I followed the recipe to the T. what could have gone wrong?
Hi Manisha - the Deep Butter cake does not have crunchy top. The crumbs are meant to be absorbed into the cake. As to the soggy parts, I don't know. The original recipe definitely had sodden parts but once I added the baking powder they went away.