Sour Cream Coffee Cake with Cinnamon Streusel

Why you’ll love it

• Extra moist and tender thanks to the sour cream.
• Thick, crunchy streusel plus a hidden cinnamon swirl.
• Great for brunch and guests: one pan, 15 generous squares.

Quick facts

Ingredients

For the streusel topping

• 1 cup (125 g) all-purpose flour
• 1 cup (200 g) packed light brown sugar
• 2 tsp ground cinnamon
• 1/4 tsp fine salt
• 1/2 cup (113 g) unsalted butter, melted

For the cinnamon swirl

• 1/3 cup (65 g) packed light brown sugar
• 1 1/2 tsp ground cinnamon

For the cake

• 2 1/2 cups (315 g) all-purpose flour
• 1 tsp baking powder
• 1 tsp baking soda
• 1/2 tsp fine salt
• 3/4 cup (170 g) unsalted butter, softened
• 1 cup (200 g) granulated sugar
• 3 large eggs, at room temperature
• 2 tsp vanilla extract
• 1 1/2 cups (360 g) full-fat sour cream, at room temperature

For the optional glaze

• 1/2 cup (60 g) powdered sugar
• 1–2 tbsp milk

Step-by-step method

1. Prepare the pan. Heat the oven to 350°F (175°C). Grease a 9×13-inch (23×33 cm) baking pan and line the bottom with parchment.

2. Make the streusel and swirl. In a bowl, mix the flour, brown sugar, cinnamon and salt for the streusel. Pour in the melted butter and stir with a fork until large, moist crumbs form. Refrigerate while you make the cake. In a small bowl, mix the brown sugar and cinnamon for the swirl.

3. Mix the dry ingredients. In a medium bowl, whisk together the flour, baking powder, baking soda and salt.

4. Cream the butter and sugar. In a large bowl, beat the butter and granulated sugar on medium-high speed for 3 minutes, until light and fluffy. Beat in the eggs one at a time, then the vanilla.

5. Finish the batter. On low speed, add the flour mixture in three additions, alternating with the sour cream in two additions, beginning and ending with the flour. Mix just until no streaks of flour remain. The batter will be thick.

6. Layer the cake. Spread half of the batter evenly in the pan and sprinkle with the cinnamon swirl mixture. Drop the remaining batter in spoonfuls over the top and gently spread it to cover. Scatter the streusel evenly over the batter, breaking up any very large clumps.

7. Bake and cool. Bake 40–45 minutes, until the streusel is golden and a toothpick inserted in the center comes out clean or with a few moist crumbs. Cool in the pan on a wire rack at least 30 minutes. If using the glaze, whisk the powdered sugar with enough milk to make a drizzle and drizzle over the warm cake. Cut into 15 squares.

How to know it is done

The coffee cake is done when the streusel is deep golden, the center springs back when lightly pressed, the edges begin to pull away from the pan and a toothpick inserted in the center comes out clean or with a few moist crumbs (about 200°F / 93°C inside). If the toothpick shows wet batter, bake 3–5 minutes more and test again.

Tips for the best result

• Use room-temperature eggs and sour cream so the batter stays smooth and the cake rises evenly.
• Do not overmix once the flour goes in; overmixing makes a dense, tough cake.
• Chill the streusel while you make the batter so it stays in big, crunchy clumps instead of melting into the cake.

Variations and substitutions

• Greek yogurt: replace the sour cream with the same amount of plain full-fat Greek yogurt.
• Pecan streusel: add 3/4 cup chopped pecans to the streusel.
• Apple: scatter 1 peeled, thinly sliced apple over the cinnamon swirl layer.
• Blueberry: fold 1 1/2 cups fresh or frozen (not thawed) blueberries into the batter.
• Bundt pan: sprinkle half the streusel in a greased 10-inch Bundt pan, add half the batter, the swirl, the rest of the batter and the rest of the streusel; bake 55–65 minutes.

Storage and reheating

Store the coffee cake covered at room temperature up to 3 days, or in the refrigerator up to 5 days. Freeze individual squares wrapped tightly up to 3 months and thaw at room temperature. Warm a square in the microwave for 15–20 seconds, or the whole cake in a 300°F (150°C) oven for 10 minutes.