Cinnamon Streusel Coffee Cake
A tender, sour cream-rich cake with a ribbon of cinnamon brown sugar streusel through the middle and a thick, crumbly layer on top. It's an easy, make-it-in-one-bowl-at-a-time breakfast bake that's perfect with coffee.
- Prep
- 25 min
- Cook
- 48 min
- Wait
- 30 min
- Total
- 1 hr 43 min
- Makes
- 1 9-inch square cake (9 generous squares)
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). This gives a smooth batter and an even crumb.
- Position an oven rack in the center and preheat the oven to 350°F (175°C).
- Measure flour by spooning it into the cup and leveling it off, or better, weigh it. Too much flour makes the cake dry.
- Plan for about 1 hour 45 minutes in total, including 30 minutes of cooling before slicing.
Prepare the panOven 350°F / 175°C
- Position a rack in the center of the oven and preheat to 350°F (175°C).
- Grease a 9×9-inch (23×23 cm) pan with the 1 teaspoon softened butter.
- Line the bottom and two opposite sides with a strip of parchment paper so it overhangs like a sling, then lightly grease the parchment.
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Ready when: Pan is lined and the oven is fully preheated.
Tip: The parchment sling lets you lift the whole cake out for neat slicing.
Mix the streusel
- In a medium bowl, whisk together 1 cup (120 g) flour, the brown sugar, ¼ cup (50 g) granulated sugar, the cinnamon and ¼ teaspoon salt, breaking up any brown sugar lumps.
- Pour in the melted butter and stir with a fork until the mixture looks like damp sand.
- Then squeeze handfuls into clumps.
- Set aside.
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Ready when: The mixture holds together in clumps when squeezed, with pea-size to marble-size crumbs.
Tip: Let the melted butter cool for a few minutes first so the streusel stays chunky instead of turning greasy.
Whisk dry ingredients
- In a separate bowl, whisk the 1¾ cups (210 g) flour, baking powder, baking soda and ½ teaspoon salt until evenly combined.
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Ready when: No streaks of baking soda or lumps remain.
Cream butter and sugar
- In a large bowl, beat the room-temperature butter and ¾ cup (150 g) granulated sugar with an electric mixer on medium-high speed for 3 minutes, scraping down the bowl once, until pale and fluffy.
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Ready when: The mixture is noticeably lighter in color and looks fluffy, like thick frosting.
Add eggs and vanilla
- Beat in the eggs one at a time on medium speed, mixing about 30 seconds after each.
- Beat in the vanilla.
- Scrape down the sides and bottom of the bowl.
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Ready when: The batter looks smooth and cohesive with no slick egg pools.
Tip: If the batter looks curdled, the eggs were too cold. It will come together once the flour is added.
Fold in flour and sour cream
- With the mixer on low, add one third of the flour mixture, then half the sour cream, mixing just until combined.
- Repeat with another third of the flour and the remaining sour cream, finishing with the last of the flour.
- Stop as soon as no dry streaks remain, then give the batter a final fold with a spatula.
- The batter will be thick.
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Ready when: The batter is thick, smooth and spoonable with no visible flour.
Tip: Don't overmix once the flour goes in, or the cake will turn tough.
Layer cake and streusel
- Spread half the batter (about 2 cups) in an even layer in the prepared pan.
- Sprinkle with about one third of the streusel, then dollop the remaining batter on top and gently spread it to the edges, being careful not to disturb the streusel layer.
- Scatter the remaining streusel evenly over the top, pressing it lightly so it adheres.
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Ready when: Top is fully and thickly covered with streusel clumps, and batter reaches all corners.
Tip: Drop the top batter in small spoonfuls across the surface, then connect them. This keeps the streusel layer from smearing.
Bake the cakeOven 350°F / 175°C
- Bake at 350°F (175°C) on the center rack for 45–50 minutes.
- Rotate the pan front to back after 30 minutes if your oven bakes unevenly.
- If the streusel browns too quickly, tent loosely with foil for the last 10 minutes.
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Ready when: A toothpick inserted in the center (through the cake, not just the streusel) comes out clean or with a few dry crumbs, the edges pull slightly from the pan, and the center feels set. Internal temperature is about 205°F (96°C).
Tip: Don't open the oven in the first 30 minutes, or the cake may sink.
Cool and slice
- Set the pan on a wire rack and cool for 30 minutes.
- Use the parchment overhang to lift the cake out, then cut into 9 squares with a serrated knife.
- Serve warm or at room temperature.
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Ready when: The pan is warm, not hot, and the cake holds its shape when lifted.
Tip: Slicing too soon makes the tender crumb fall apart.
Good to know
Tips
- Use room-temperature ingredients. Cold sour cream or eggs make the batter lumpy and the cake denser.
- Pinch the streusel into large clumps before sprinkling for a bakery-style crumbly top.
- Check for doneness by testing the center cake, not the streusel, since a toothpick that hits melted sugar can look wet.
- Add ½ cup (60 g) chopped pecans or walnuts to the streusel for extra crunch.
Make ahead
"Bake the cake up to 1 day ahead and store covered at room temperature. Or prepare the streusel up to 3 days ahead and refrigerate it in an airtight container. Bring to room temperature before using. You can also freeze the baked cake for up to 2 months."
Storage & reheating
"Room temperature: cover tightly and keep up to 2 days. Refrigerator: up to 5 days in an airtight container; bring to room temperature or warm before serving. Freezer: wrap squares individually and freeze up to 2 months; thaw overnight at room temperature. Reheat a square at 325°F (160°C) for 8–10 minutes or microwave for 15–20 seconds."
Substitutions
- full-fat sour cream → full-fat plain Greek yogurt. Use the same weight (230 g). The cake will be slightly tangier but just as moist.
- light brown sugar → dark brown sugar. Gives a deeper molasses flavor. Use the same amount, packed.
- unsalted butter → salted butter. Use the same amount and reduce the cake's salt to ¼ teaspoon.
- all-purpose flour → gluten-free 1:1 baking flour. Use the same weight. Let the batter rest 10 minutes before baking, and expect a slightly more crumbly texture.
