This sour-cream coffee cake has a soft, close crumb, a narrow cinnamon-sugar ribbon, and a buttery streusel that stays crisp at the edges. It is baked in an 8-inch square pan and cut into nine generous squares—easy to portion for a brunch table or an afternoon coffee break.
The batter is thicker than a pourable cake batter. That is intentional: a thick layer supports the cinnamon filling and keeps it from sinking to the bottom. Use softened butter and room-temperature sour cream so the batter combines smoothly without needing extra mixing.
Build a tender crumb without overmixing
Start with butter that yields when pressed but still feels cool, not shiny or melted. Cream it with the sugar for two to three minutes until lighter and fluffy; this step helps make the cake tender. Add the eggs one at a time so the mixture stays emulsified. If it looks slightly curdled after an egg, add a spoonful of the measured flour and continue mixing.
Alternate the flour mixture with sour cream on low speed, beginning and ending with flour. Stop as soon as the last dry streak disappears. Mixing longer can develop more gluten and make the square cake firm. The sour cream adds moisture and a gentle tang that balances the sweet cinnamon layer.
Keep the cinnamon layer in the middle
Spread half the batter in the lined pan, then scatter the brown-sugar cinnamon mixture evenly, leaving a small border around the edge. Add the remaining batter in spoonfuls rather than pouring it in one spot; spread it carefully with an offset spatula or the back of a spoon. A few small gaps are fine and will close in the oven. Do not swirl the layers together, or the ribbon can disappear into the crumb.
How to tell when the center is baked
Begin checking around 38 minutes because ovens and pan materials vary. The streusel should look dry and lightly golden, and the center should spring back gently when tapped. A tester inserted into cake (avoiding the cinnamon seam) should come out with a few moist crumbs, not streaks of raw batter. If the topping is browning before the center is done, tent the pan loosely with foil for the final minutes.
Let the cake cool in the pan for 20 minutes before lifting it out. Cutting it while very hot can compress the soft crumb and smear the cinnamon layer. It is especially good slightly warm, but the ribbon and streusel are easier to see once the slices have settled.
Make-ahead, storage, and variations
For a calmer morning, measure the dry ingredients and mix the streusel the night before; cover and refrigerate the streusel. Bake the cake the day you plan to serve it. Keep leftovers covered at room temperature for up to two days or refrigerate for up to five. Bring a slice to room temperature, or warm it briefly in a low oven; microwaving can soften the streusel.
For a nutty variation, replace up to 1/4 cup of the streusel flour with finely chopped pecans. Keep the pieces small so the topping remains easy to cut. For another fruit-forward bake, see our Blueberry Crisp with a Buttery Oat Topping; for a citrus loaf with a different crumb, try the Lemon Poppy Seed Loaf.
Estimated nutrition
Approximate values per square, based on cutting the pan into nine servings. The estimate varies with the brands and exact ingredients used.
| Nutrient | Estimated amount |
|---|---|
| Calories | 415 kcal |
| Carbohydrates | 54 g |
| Protein | 5 g |
| Total fat | 19 g |
| Saturated fat | 12 g |
| Fiber | 1 g |
| Total sugars | 32 g |
| Sodium | 320 mg |
Nutrition figures are ingredient-based estimates. Images accompanying this recipe are illustrative.
Cinnamon Streusel Coffee Cake with a Soft Sour-Cream Crumb
Ingredients
Equipment
Method
- Heat the oven to 350°F (175°C). Grease an 8-inch square metal pan and line it with a parchment sling. For the streusel, mix the flour, brown sugar, cinnamon, and salt; work in the cold butter with your fingertips until pea-size crumbs form. Refrigerate while making the batter.
- Stir the cinnamon-ribbon brown sugar and cinnamon together in a small bowl. Whisk the cake flour, baking powder, baking soda, and salt in a separate bowl.
- Beat the softened butter and granulated sugar on medium speed until pale and fluffy, about 2 to 3 minutes. Beat in the eggs one at a time, then the vanilla, scraping the bowl once.
- With the mixer on low, add the dry mixture in three additions, alternating with the sour cream in two additions. Begin and end with the dry ingredients; stop as soon as no dry flour remains. The batter will be thick.
- Spread half the batter in the pan. Sprinkle the cinnamon mixture evenly over it, keeping a narrow border at the edges. Dollop the remaining batter on top and spread gently, then scatter over the chilled streusel without pressing it down.
- Bake for 38 to 45 minutes, until the center springs back lightly and a tester comes out with a few moist crumbs but no wet batter. If the top browns early, tent loosely with foil. Cool in the pan for 20 minutes, then lift out by the parchment and cool until just warm before slicing.
