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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- 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
- 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
- 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.
- 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.
- 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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