Ingredients:

  • 1 cup (120g) all-purpose flour
  • 1/2 cup (100g) granulated sugar
  • 1/4 cup (50g) packed light brown sugar
  • 1/2 teaspoon ground cinnamon
  • 1/4 teaspoon salt
  • 6 tablespoons (85g) cold unsalted butter, cut into cubes
  • 1/4 cup (50g) granulated sugar
  • 2 teaspoons ground cinnamon
  • 2 cups (250g) all-purpose flour
  • 1 teaspoon baking powder
  • 1/2 teaspoon baking soda
  • 1/2 teaspoon salt
  • 1/2 cup (115g) unsalted butter, softened
  • 1 cup (200g) granulated sugar
  • 2 large eggs
  • 1 teaspoon vanilla extract
  • 1 cup (240ml) sour cream or plain yogurt

Instructions:

  1. Prepare the Crumb Topping: Combine dry ingredients. Cut in the cold butter using a pastry blender or your fingers until the mixture resembles coarse crumbs. Chill until ready to use.
  2. Make the Cinnamon Swirl: Whisk together the sugar and cinnamon in a small bowl. Set aside.
  3. Make the Cake Batter: Whisk together flour, baking powder, baking soda, and salt in a bowl. Cream together the softened butter and sugar until light and fluffy. Beat in the eggs one at a time, then stir in the vanilla.
  4. Combine Wet and Dry Ingredients: Gradually add the dry ingredients to the wet ingredients, alternating with the sour cream or yogurt, beginning and ending with the dry ingredients. Mix until just combined. Do not overmix!
  5. Assemble the Cake: Spread half of the batter into the prepared pan. Sprinkle with half of the cinnamon-sugar mixture. Top with the remaining batter and sprinkle with the remaining cinnamon-sugar.
  6. Add the Crumb Topping: Generously sprinkle the crumb topping evenly over the cake batter.
  7. Bake: Bake in a preheated oven at 350°F (175°C) for 40-50 minutes, or until a toothpick inserted into the center comes out clean or with a few moist crumbs.
  8. Cool: Let the cake cool in the pan for 10-15 minutes before removing the sides of the springform pan. Transfer to a wire rack to cool completely.