Cinnamon Streusel Coffee Cake

A tender, delicate sour cream cake with not one, but two layers of cinnamon crumbs – both inside and on top of the cake.

Cinnamon Streusel Coffee Cake

Ingredients
For the streusel:
  1. ¾ cup plus 2 tablespoons (125 grams or 4.5 ounces) all-purpose flour
  2. ⅓ cup (65 grams or 2.3 ounces) granulated sugar
  3. ⅓ cup (65 grams or 2.3 ounces) brown sugar (light or dark)
  4. 2 teaspoons ground cinnamon
  5. ⅛ teaspoon salt
  6. 6 tablespoons (85 grams or 3 ounces) butter, melted

For the cake:
  1. 1½ cups (210 grams or 7.4 ounces) all-purpose flour
  2. 1¼ teaspoons baking powder
  3. ¼ teaspoon baking soda
  4. ¼ teaspoon salt
  5. ½ cup (1 stick or 115 grams) butter, softened to room temperature
  6. 1 cup (200 grams or 7 ounces) granulated sugar
  7. 2 large eggs, at room temperature
  8. 1.5 teaspoons vanilla extract
  9. 1 cup sour cream

Instructions
  • Preheat oven to 350F/180C degrees. Grease a 9-inch pan (round or square). Set aside.
  • To make the streusel: In a medium bowl, whisk together flour, granulated sugar, brown sugar, cinnamon and salt. Add the melted butter and mix with a fork until the mixture is uniformly moistened and crumbs form. Set aside.
  • To make the cake: In a medium bowl sift together flour, baking powder, baking soda and salt. Set aside.
  • In a mixer bowl fitted with the paddle attachment, beat the butter on medium speed for one minute until creamy. Add sugar and beat on medium speed for about 3 minutes, until light and fluffy. Beat in the eggs, one at a time until combined. Scrape down the sides and bottom of the bowl as necessary. Beat in vanilla extract. On low speed, beat in the flour mixture in 3 additions, alternating it with the sour cream in 2 additions (starting and ending with the flour). Do not overmix.