This lemon blueberry crumb cake has a soft, buttery vanilla crumb loaded with juicy berries and a thick layer of cinnamon streusel on top.
The batter comes together with melted butter and sour cream, and the streusel is mixed with a fork in minutes. Slice it warm for brunch, afternoon coffee, or a simple dessert.
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Why This Lemon Blueberry Crumb Cake Recipe Works
Melted butter keeps the crumb tender and moist, while sour cream adds a gentle tang that balances the sugar. Using both milk and sour cream gives a batter that is thick enough to hold the berries without letting them sink to the bottom.
Tossing the blueberries in a little flour and sugar before folding them in keeps the juices from bleeding into the batter. A splash of lemon juice brightens the fruit, and fresh lemon zest in the batter carries the flavor all the way through.
The streusel is made with melted butter instead of cold butter, so there is no cutting in and no food processor. It bakes into big, craggy clumps that stay crisp on top and soften slightly where they meet the cake.
Ingredients for Lemon Blueberry Crumb Cake
- 2/3 cup all-purpose flour, for the crumb topping
- 1/2 cup superfine sugar, for the crumb topping
- 1/2 tsp ground cinnamon, for the crumb topping
- 1/8 tsp kosher salt, for the crumb topping
- 4 tbsp unsalted butter, melted, for the crumb topping
- 1/4 tsp vanilla extract, for the crumb topping
- 1 1/3 cups all-purpose flour, for the cake
- 2 tsp baking powder, for the cake
- 1/4 tsp kosher salt, for the cake
- 3/4 cup superfine sugar, for the cake
- 1 tsp vanilla extract, for the cake
- 1 tbsp lemon zest, for the cake
- 2 large eggs, for the cake
- 6 tbsp unsalted butter, melted and slightly cooled, for the cake
- 1/3 cup sour cream, at room temperature, for the cake
- 1/3 cup whole milk, at room temperature, for the cake
- 1 lb fresh blueberries, for the filling
- 2 tsp lemon juice, for the filling
- 2 tbsp superfine sugar, for the filling
- 3 tbsp all-purpose flour, for the filling
Flour: All-purpose flour gives a soft, even crumb. Use the same type for the streusel, the batter, and the berry coating.
Superfine sugar: It dissolves quickly in the batter. Regular granulated sugar works if you whisk a little longer.
Sour cream: It keeps the cake moist and adds tang. Plain yogurt is an easy swap.
Blueberries: Fresh berries are ideal. Frozen berries work too if you toss them straight from the freezer without thawing.
Lemon: You need the zest for the batter and the juice for the berries, so zest the lemon first, then squeeze it.
How to Make Lemon Blueberry Crumb Cake
1. Prep the pan. Heat the oven to 400 degrees F. Line the bottom of an 8 inch springform pan with parchment paper and set it aside.
2. Make the streusel. Stir the flour, sugar, cinnamon, and salt in a medium bowl with a fork. Pour in the melted butter and vanilla, then mix until the flour is damp but still lumpy.
3. Coat the berries. Toss the blueberries with the lemon juice, then with the sugar and flour. Set the bowl aside while you mix the batter.
4. Mix the batter. Whisk the flour, baking powder, salt, sugar, and lemon zest. Add the eggs, melted butter, sour cream, milk, and vanilla and stir until smooth.
5. Fold and fill. Fold the berries in gently, spread the batter evenly in the pan, and scatter the streusel over the top in large clumps.
6. Bake and cool. Bake for 35 to 40 minutes, until a toothpick in the center comes out clean and the top is golden. Cool in the pan for at least 20 minutes before unmolding.
How to Serve Lemon Blueberry Crumb Cake
Serve the cake warm or at room temperature with a dusting of powdered sugar, whipped cream, or a scoop of vanilla ice cream. It pairs well with another streusel topped cake on a brunch table, and it sits nicely beside blueberry crumble muffins for a bakery style spread. For a richer dessert plate, add a slice of classic cheesecake, and a glass of a berry kefir smoothie keeps the menu light.
How to Store and Reheat Lemon Blueberry Crumb Cake
Cover leftovers and keep them at room temperature for up to 2 days or in the refrigerator for up to 5 days. Wrap individual slices tightly and freeze for up to 3 months. Warm a slice in a 300 degrees F oven or for 15 seconds in the microwave to refresh the crumb.
Tips and Variations for Lemon Blueberry Crumb Cake
Room temperature dairy. Cold sour cream and milk can firm up the melted butter. Take them out of the refrigerator before you start.
Do not overmix. Stir the batter only until no dry flour remains for a tender crumb.
Keep the streusel lumpy. Stop mixing when the flour is damp and clumpy. A dry sandy mix will not form large crumbs.
Frozen berries. Toss them in the flour and sugar while frozen and add about 5 minutes to the bake time.
Test early. Ovens vary. Start checking at 35 minutes and cover loosely with foil if the top browns too fast.
Pan size. A 9 inch springform pan works too and gives a slightly thinner cake that bakes a little faster.
Flavor swaps. Try raspberries, or use half blueberries and half chopped strawberries.
Egg safety. Do not taste the batter, since it contains raw egg. For general guidance on handling eggs safely, see the Montana State University Extension egg fact sheet.
Frequently Asked Questions About Lemon Blueberry Crumb Cake
Can I make this lemon blueberry crumb cake ahead of time?
Yes. Bake it a day ahead, cool it fully, cover it, and keep it at room temperature. The crumb topping stays crisp for about a day, and a short rewarm in the oven brings it back.
Can I use frozen berries in this lemon blueberry crumb cake?
Yes. Do not thaw them. Toss them in the flour and sugar mixture straight from the freezer and fold them in at the last second so they do not bleed into the batter.
Why did the berries sink in my lemon blueberry crumb cake?
Thin batter and wet berries both cause sinking. Coating the berries in flour and sugar and measuring the milk accurately keeps them suspended.
Can I use yogurt instead of sour cream?
Plain full fat yogurt works in the same amount. Low fat yogurt makes a slightly drier crumb.
Can I bake it in a different pan?
A 9 inch round pan or an 8 inch square pan both work. Check for doneness a few minutes early with a toothpick.
Lemon Blueberry Crumb Cake
Equipment
- 8 inch springform pan
- Parchment paper
- Medium mixing bowl
- Large mixing bowl
- Whisk
- Wire cooling rack
Ingredients
Main Ingredients
- ⅔ cup all-purpose flour for the crumb topping
- ½ cup superfine sugar for the crumb topping
- ½ tsp ground cinnamon for the crumb topping
- ⅛ tsp kosher salt for the crumb topping
- 4 tbsp unsalted butter melted, for the crumb topping
- ¼ tsp vanilla extract for the crumb topping
- 1 ⅓ cup all-purpose flour for the cake
- 2 tsp baking powder for the cake
- ¼ tsp kosher salt for the cake
- ¾ cup superfine sugar for the cake
- 1 tsp vanilla extract for the cake
- 1 tbsp lemon zest for the cake
- 2 large eggs for the cake
- 6 tbsp unsalted butter melted and slightly cooled, for the cake
- ⅓ cup sour cream at room temperature, for the cake
- ⅓ cup whole milk at room temperature, for the cake
- 1 lb fresh blueberries for the filling
- 2 tsp lemon juice for the filling
- 2 tbsp superfine sugar for the filling
- 3 tbsp all-purpose flour for the filling
Instructions
Cooking
- Heat the oven. Set a rack in the center and heat the oven to 400 degrees F. Line the bottom of an 8 inch springform pan with parchment paper.
- Mix the crumb. Combine 2/3 cup flour, 1/2 cup sugar, the cinnamon, and 1/8 tsp salt with a fork. Add 4 tbsp melted butter and 1/4 tsp vanilla and mix until the flour looks wet and lumpy.
- Zest and juice. Zest the lemon first for the cake, then squeeze 2 tsp juice for the berries.
- Coat the berries. Toss the blueberries with the lemon juice until glossy, sprinkle with 2 tbsp sugar and 3 tbsp flour, and toss again until no dry flour remains.
- Make the dry mix. In a large bowl, whisk 1 1/3 cups flour, the baking powder, 1/4 tsp salt, 3/4 cup sugar, and the lemon zest.
- Add the wet ingredients. Stir in the eggs, 6 tbsp melted butter, sour cream, milk, and 1 tsp vanilla until the batter is smooth with no streaks.
- Fill the pan. Fold in the coated berries, scrape the batter into the pan, smooth the top, and sprinkle the crumb over it in clumps.
- Bake. Bake for 35 to 40 minutes, until the crumb is golden and a toothpick in the center comes out clean. Cool for 20 minutes in the pan, then release the springform.
