This is a single-layer cake with fresh blueberries folded into a sour cream batter, finished with a simple flour-and-butter crumble on top. It bakes in about 45 minutes and serves 8. The honest reason to make it: the crumble gives you the texture of a coffee cake and the flavor of a fruit crisp, without any of the fuss of frosting or layering.
The short version of why this works
Two things carry this cake. First, the sour cream. It keeps the crumb soft and adds a mild tang that stops the cake from tasting flat or one-note alongside the lemon. Full-fat is worth it here — low-fat versions release more water and can make the center sink. Second, cold butter in the crumble topping. If the butter warms up before it goes into the oven, the crumble melts into a solid crust instead of staying loose and sandy. Work fast with your fingertips, or use a box grater to shred frozen butter straight into the flour and sugar — that method is more forgiving and gives you even, pea-sized pieces without overworking it.
Common problems and fixes
- Blueberries all sink to the bottom: Toss the rinsed, fully dried blueberries in a teaspoon of flour before folding them in. The light coating helps them stay suspended in the batter during baking.
- Crumble topping slides off the sides: The batter is thick enough to support the topping, but if yours seems loose, chill the assembled unbaked cake for 10 minutes before it goes in the oven. This firms the batter slightly and anchors the crumble.
- Cake is done on the edges but still wet in the center: Springform pans heat unevenly. Placing the pan on a baking sheet (as the recipe directs) helps, but if your oven runs hot, tent the top loosely with foil at the 30-minute mark to slow the edges while the center catches up.
- Crumble is pale and soft after baking: Your oven temperature may be slightly low. Give the cake an extra 3–5 minutes uncovered at the end. The crumble should look golden, not just set.
- Cake sticks when you release the springform ring: Run a thin knife or offset spatula around the inside edge of the pan before unclipping the ring, even if you greased it well. Do this after the 15-minute rest, while the cake is still slightly warm.
Shopping notes
Use organic lemons if you can find them easily — the zest is the most concentrated lemon flavor in this cake, and unwaxed organic skin tastes cleaner. If you only have conventional lemons, scrub them under hot water and dry them before zesting. For the blueberries, fresh is strongly preferred; frozen berries release too much liquid and can turn the batter purple and wet. Skip the garnish — not worth the extra dish. The crumble top already looks good on its own straight from the pan.
Lemon Blueberry Crumble Cake
Equipment
- 9-inch Springform Pan
- Mixing Bowls
- Electric Mixer
- Rubber spatula
- Baking sheet
Ingredients
For the Crumble Topping:
- ½ cup all-purpose flour
- ½ cup granulated sugar
- ¼ cup unsalted butter cold, cubed
For the Cake:
- 1 ½ cups all-purpose flour
- 1 teaspoon baking powder
- ½ teaspoon baking soda
- ¼ teaspoon salt
- ½ cup unsalted butter softened
- â…” cup granulated sugar
- 2 large eggs room temperature
- 1 teaspoon vanilla extract
- 2 tablespoons lemon zest from organic lemons
- ¼ cup fresh lemon juice
- ½ cup sour cream full fat
- 1 cup fresh blueberries rinsed and dried
Instructions
- Preheat your oven to 350°F (175°C). Grease a 9-inch springform pan and line the bottom with parchment paper.
For the Crumble Topping:
- In a bowl, combine 1/2 cup flour and 1/2 cup granulated sugar. Add the cold, cubed butter and mix with your fingertips until the mixture resembles coarse crumbs. Set aside.
For the Cake:
- In another bowl, whisk together 1 1/2 cups flour, baking powder, baking soda, and salt. In a separate large mixing bowl, beat the softened butter and 2/3 cup granulated sugar until light and fluffy, about 3 minutes.
- Add the eggs one at a time, mixing well after each addition. Stir in the vanilla extract, lemon zest, and lemon juice until well combined. Gradually mix in the dry ingredients, alternating with sour cream, starting and ending with the dry ingredients.
- Gently fold in the blueberries and pour the batter into the prepared pan. Sprinkle the crumble topping evenly over the batter.
- Place the pan on a baking sheet and bake in the preheated oven for 45 minutes or until a toothpick inserted into the center comes out clean with just a few moist crumbs.
- Allow the cake to cool in the pan on a wire rack for 15 minutes. Then remove the springform ring and let cool completely before serving.
Notes
- To intensify the lemon flavor, add a tablespoon of lemon zest to the crumble topping.
- For a dairy-free version, substitute the sour cream with a non-dairy yogurt.
Nutrition
Common questions
Can I use a regular 9-inch round cake pan instead of a springform pan?
Yes, but getting the cake out cleanly is harder. Line the bottom and sides with parchment, let the cake cool completely in the pan, then invert it onto a plate and flip it right-side up — the crumble topping is fragile when warm, so don’t rush it.
How do I know when the cake is actually done?
A toothpick inserted in the center should come out with a few moist crumbs, not wet batter. The edges will pull slightly from the pan sides and the crumble will be golden brown. If the toothpick hits a blueberry, try a different spot — berry juice can look like raw batter.
Can I make this the night before?
Yes, and it holds up well. Store it covered at room temperature for up to 24 hours — the crumble softens slightly overnight but the flavor is just as good. For longer storage, refrigerate it and bring it back to room temperature for 30 minutes before serving.
Try these next
- Mediterranean Sunshine Lemon Crumble Bars
- Rustic Blackberry Almond Cake
- Zesty Lemon Thyme Shortbread Bars
- Provence-Inspired Blackberry Lavender Crumble