Blueberry Streusel Cake
From the kitchen of CarlyA tender butter cake studded with blueberries and topped with a cinnamon-brown sugar streusel. Tangy sour cream keeps the crumb moist and delicate, while the crispy topping adds necessary texture. Perfect for breakfast or afternoon snacking.
A tender, sour-cream cake studded with juicy blueberries and a two-layer streusel topping that stays crisp even after cooling. The trick is adding the second half of the crumble halfway through baking, which keeps the topping from sinking and guarantees those buttery, cinnamon-sugar clusters in every bite. This is the kind of cake that works for breakfast, lunch, or a casual dessert with whipped cream.
- Prep
- n/a
- Cook
- n/a
- Total
- n/a
- Servings
- 4
- Difficulty
- medium
Ingredients
4 servings
- 1 cupall-purpose flour
- 1 tbspplus 1 teaspoon packed dark brown sugar
- 1 tbspplus 1 teaspoon granulated sugar
- 3/4 tspcinnamon
- 1/2 stickcold unsalted butter, cut into 1/2-inch pieces
- 1 cupall-purpose flour
- 1 tspbaking powder
- 1/4 tspbaking soda
- 1/2 tspsalt
- 1/2 cupsour cream
- 3/4 tsppure vanilla extract
- 1/2 stickunsalted butter, softened
- 3/4 cupgranulated sugar
- 1 largeegg
- 1/2 lbblueberries
- 1sweetened whipped cream
Instructions
Position a rack in the middle of the oven and heat to 350°F. Line the bottom and sides of a 9-inch square baking pan with heavy-duty foil, leaving an overhang on 2 sides, then butter the foil and dust it with flour, knocking out any excess.
For the streusel, combine the flour, both sugars, cinnamon, and a pinch of salt in a large bowl. Work the cold butter in with your fingertips or a pastry blender, pressing and smearing until the mixture comes together in large clumps.
In a separate bowl, whisk the flour, baking powder, baking soda, and salt until evenly combined.
Stir the sour cream and vanilla together in a small bowl and set aside.
In a large bowl, beat the softened butter and granulated sugar with an electric mixer on medium-high until the mixture is pale and fluffy, about 5 minutes. Add the egg and beat until fully incorporated.
Drop the speed to low and mix in the flour mixture in 3 batches, alternating with the sour cream mixture, stirring just until each addition disappears into the batter.
Using a rubber spatula, fold the blueberries in gently so they stay mostly whole.
Scrape the batter into the prepared pan and smooth the top with an offset spatula. Scatter half the streusel evenly across the surface.
Slide the pan into the oven and bake for 25 minutes, then pull it out and crumble the remaining streusel over the top. Return to the oven and bake until a wooden pick inserted into the center comes out clean, about 25 minutes more. Let the cake cool in the pan for 10 minutes, then lift it out by the foil overhang and transfer to a rack to cool completely.
Tips from the kitchen
- Don't overmix the batter once you add the flour and sour cream. Stir until just combined, fold in the blueberries gently, and call it done. Overworking will make the crumb tough.
- Toss your blueberries in a tablespoon of flour before folding them in. It keeps them from sinking to the bottom during baking.
- The streusel works best when the butter is cold and cut into small pieces. Use your fingertips to work it into clumps, not a fine meal. Those clumps become the crispy texture you want.
Variations
- Swap blackberries or raspberries for the blueberries, keeping the same amount. Softer berries will break down slightly, but the cake still holds together.
- Add 1/2 teaspoon of lemon zest to the cake batter for brightness that plays well with the berries.
- Use a mix of dark brown sugar and white sugar in the streusel, or go all brown sugar for deeper molasses flavor and chewier clumps.
- Stir 1/4 cup chopped pecans or almonds into the streusel topping for crunch and nuttiness.
Make ahead and storage
Keep it covered at room temperature for up to 3 days. It's not a freezer-friendly cake because the streusel loses its crunch when thawed, but it tastes just as good cold as it does warm.