Blueberry Sour Cream Coffee Cake

Name: Blueberry Sour Cream Coffee Cake
Prep time: 30 min
Cook time: 45 min
Total time: 1 h 15 min
Yield: 9 servings
Cuisine: American
Ingredients: ¾ cup (94 g) all-purpose flour, spooned and leveled; ⅓ cup (70 g) light brown sugar, packed; ¼ cup (50 g) granulated sugar; 1 tsp (3 g) ground cinnamon; ¼ tsp (1½ g) fine salt; 6 tbsp (85 g) unsalted butter, melted and slightly cooled; 2 cups (250 g) all-purpose flour, spooned and leveled; 1½ tsp (6 g) baking powder; ½ tsp (3 g) baking soda; ½ tsp (3 g) fine salt; 8 tbsp (113 g) unsalted butter, softened to room temperature (it should dent easily when pressed), plus a little extra for greasing the pan; ¾ cup (150 g) granulated sugar; 2 whole (100 g) large eggs, at room temperature; 2 tsp (10 ml) pure vanilla extract; 1 tsp (2 g) lemon, zest only, finely grated; 1 cup (240 g) full-fat sour cream, at room temperature; 1½ cups (225 g) blueberries, fresh (rinsed and fully dried) or frozen (do not thaw); 1 tbsp (8 g) all-purpose flour, for tossing with the blueberries

From the MyKitchenBank Kitchen

A tender, tangy sour cream cake studded with juicy blueberries and topped with a thick layer of buttery cinnamon streusel. It's easy to mix by hand, works with fresh or frozen berries, and is perfect with morning coffee.

Prep: 30 min
Cook: 45 min
Wait: 30 min
Total: 1 hr 45 min
Makes: 1 cake (9 squares), baked in a 9-inch square pan

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Ingredients

9 servings

For the streusel
¾ cup (94 g) all-purpose flour, spooned and leveled
⅓ cup (70 g) light brown sugar, packed
¼ cup (50 g) granulated sugar
1 tsp (3 g) ground cinnamon
¼ tsp (1.5 g) fine salt
6 tbsp (85 g) unsalted butter, melted and slightly cooled
For the cake
2 cups (250 g) all-purpose flour, spooned and leveled
1½ tsp (6 g) baking powder
½ tsp (3 g) baking soda
½ tsp (3 g) fine salt
8 tbsp (113 g) unsalted butter, softened to room temperature (it should dent easily when pressed), plus a little extra for greasing the pan
¾ cup (150 g) granulated sugar
2 whole (100 g) large eggs, at room temperature
2 tsp (10 ml) pure vanilla extract
1 tsp (2 g) lemon, zest only, finely grated
1 cup (240 g) full-fat sour cream, at room temperature
1½ cups (225 g) blueberries, fresh (rinsed and fully dried) or frozen (do not thaw)
1 tbsp (8 g) all-purpose flour, for tossing with the blueberries

Equipment (9)

9×9-inch (23×23 cm) square metal or ceramic baking pan
Large mixing bowl and 2 medium mixing bowls
Electric hand mixer or stand mixer with paddle attachment
Rubber spatula
Zester or microplane
Measuring cups and spoons, or a kitchen scale
Parchment paper
Wire cooling rack
Toothpick or thin skewer

Steps

Before you start

Take the butter, eggs, and sour cream out of the fridge about 1 hour ahead so they are at room temperature (about 68–70°F / 20–21°C). Cold ingredients make a curdled-looking batter and a denser cake.
Measure flour by spooning it into the measuring cup and leveling it off, or better, weigh it. Scooping packs in extra flour and makes the cake dry.
If using frozen blueberries, do not thaw them. Use them straight from the freezer to prevent purple streaks, and expect about 5 extra minutes of baking.
Total time is about 1 hour 45 minutes, including 30 minutes of cooling before slicing.

1
Heat oven, prep panOven 350°F / 175°C
- Position a rack in the center of the oven and heat to 350°F (175°C).
- Lightly grease a 9×9-inch (23 cm) square pan with a little softened butter.
- Line the bottom and two opposite sides with a strip of parchment paper, leaving a 2-inch overhang on each side to use as handles.
- Lightly grease the parchment.
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Ready when: The oven is fully preheated and the pan is lined with no bare spots on the bottom.
Tip: The parchment handles let you lift the whole cake out later for clean slicing.
2
Make the streusel
- In a medium bowl, stir together the streusel flour, brown sugar, granulated sugar, cinnamon, and salt, breaking up any brown sugar lumps.
- Pour in the melted butter and stir with a fork until the mixture looks like damp sand with some pea-sized and larger clumps.
- Squeeze a handful so it holds together, then set the bowl aside.
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Ready when: The mixture forms clumps when squeezed and no dry flour remains at the bottom of the bowl.
Tip: Let the melted butter cool for a few minutes first. If it is too hot, the streusel turns pasty instead of crumbly.
3
Whisk the dry ingredients
- In a second medium bowl, whisk together 2 cups (250 g) flour, the baking powder, baking soda, and ½ teaspoon salt for 20 seconds until evenly combined.
- Set aside.
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Ready when: The mixture is one uniform pale color with no streaks of baking soda.
4
Cream butter and sugar
- In a large bowl, beat the softened butter and ¾ cup (150 g) granulated sugar with an electric mixer on medium-high speed for 3 minutes.
- Stop once to scrape down the sides and bottom of the bowl.
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Ready when: The mixture is noticeably paler, fluffy, and looks like thick whipped frosting.
Tip: Butter that is too warm or greasy won't hold air. It should be cool to the touch and about 65–68°F (18–20°C).
5
Beat in eggs and flavorings
- Add the eggs one at a time, beating on medium speed for 30 seconds after each and scraping the bowl as needed.
- Beat in the vanilla and lemon zest until combined.
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Ready when: The mixture looks smooth, glossy, and thick, with no visible streaks of egg.
Tip: If the mixture looks slightly curdled, keep going. It will smooth out once the flour is added.
6
Alternate flour and sour cream
- With the mixer on low speed, add one-third of the flour mixture and mix just until the streaks of flour disappear.
- Add half of the sour cream and mix until just combined.
- Repeat with another third of the flour, the remaining sour cream, and finally the last third of the flour.
- Stop mixing as soon as no dry flour remains.
- The batter will be thick and spreadable.
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Ready when: The batter is thick, creamy, and uniform with no dry pockets of flour.
Tip: Overmixing after the flour goes in develops gluten and makes the cake tough, so scrape the bowl and fold the last few strokes by hand.
7
Fold in blueberries
- In a small bowl, gently toss the blueberries with the 1 tablespoon (8 g) flour until lightly coated.
- Fold them into the batter with a rubber spatula using about 8 gentle strokes, just until evenly distributed.
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Ready when: The berries are spread evenly through the batter and the batter is still mostly pale, not purple.
Tip: Fold gently so the berries don't burst. Frozen berries bleed color quickly if you stir too much.
8
Assemble the cake
- Scrape the batter into the prepared pan and spread it into an even layer, pushing it into the corners with the back of the spatula.
- Scatter the streusel evenly over the top, squeezing it into large clumps as you go and leaving it loose rather than pressing it down.
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Ready when: The batter is level and fully covered by a thick, craggy layer of streusel.
9
Bake the cakeOven 350°F / 175°C
- Bake at 350°F (175°C) on the center rack for 42 to 48 minutes (add about 5 minutes if using frozen berries).
- Check at 40 minutes.
- If the streusel is browning too fast, loosely tent the pan with foil.
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Ready when: The streusel is deep golden brown, the edges pull slightly from the pan, and a toothpick inserted into a cake spot (not a berry) comes out clean or with a few dry crumbs. The center springs back lightly when pressed.
Tip: A toothpick that hits a blueberry will look wet. Test in a spot between berries.
10
Cool and slice
- Set the pan on a wire rack and let the cake cool for 30 minutes.
- Use the parchment handles to lift the cake out of the pan, then cut into 9 squares with a sharp knife.
- Serve warm or at room temperature.
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Ready when: The pan is only warm to the touch and the cake holds clean edges when cut.
Tip: Cutting too early while the berry juices are molten makes the squares fall apart.

Good to know

Tips

Weigh the flour if you can. Too much flour is the most common reason coffee cakes bake up dry.
Toss the berries in flour and fold them in at the very end so they stay suspended and don't sink or bleed.
Keep the streusel in large, loose clumps for a bakery-style crunchy top. Don't press it into the batter.
Use a metal or ceramic pan. A glass pan can over-brown the edges, so if you use one, lower the oven to 325°F (165°C) and bake a few minutes longer.

Make ahead

"Make the streusel up to 2 days ahead and refrigerate it in an airtight container. Bake the cake fully a day ahead and store it covered at room temperature. It tastes just as good, and the crumb gets even moister overnight."

Storage & reheating

"Room temperature: cover tightly and keep up to 2 days. Refrigerator: up to 5 days in an airtight container. Freezer: wrap individual squares in plastic and foil and freeze up to 3 months; thaw overnight at room temperature. To reheat, warm a square in a 325°F (165°C) oven for 8–10 minutes, or microwave for 15–20 seconds."

Substitutions

full-fat sour cream → full-fat plain Greek yogurt. Use the same weight (240 g). The cake will be very slightly tangier and a little less rich.
blueberries → raspberries, blackberries, or chopped pitted cherries. Use the same weight. Raspberries are fragile, so fold them in extra gently.
unsalted butter → salted butter. Use the same amount and reduce the cake's ½ teaspoon salt to ¼ teaspoon.
lemon → orange zest. Use the same amount for a sweeter, softer citrus note.