Ingredients:

  • ½ cup (1 stick / 113g) unsalted butter, cold, cut into cubes
  • ¾ cup (150g) all-purpose flour
  • ½ cup (100g) granulated sugar
  • ¼ cup (50g) packed light brown sugar
  • 1 teaspoon ground cinnamon
  • Pinch of salt
  • 2 cups (250g) all-purpose flour
  • 1 teaspoon baking powder
  • ½ teaspoon baking soda
  • ½ teaspoon salt
  • ¾ cup (1 ½ sticks / 170g) unsalted butter, softened
  • 1 ¼ cups (250g) granulated sugar
  • 2 large eggs
  • 1 teaspoon vanilla extract
  • 1 cup (240ml) sour cream or plain Greek yogurt
  • ¼ cup (50g) granulated sugar
  • 1 tablespoon ground cinnamon

Instructions:

  1. Prep the Crumb Topping: Combine cold butter, flour, sugars, cinnamon, and salt in a bowl. Cut the butter into the dry ingredients using a pastry blender or your fingertips until the mixture resembles coarse crumbs. Chill while you prepare the cake batter.
  2. Prepare the Cake Batter: Whisk together flour, baking powder, baking soda, and salt in a bowl. Set aside.
  3. Cream Butter and Sugar: In a separate bowl, cream together the softened butter and sugar until light and fluffy.
  4. Add Eggs and Vanilla: Beat in the eggs one at a time, then stir in the vanilla extract.
  5. Alternate Dry and Wet 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. Don't overmix!
  6. Assemble the Cake: Pour half of the cake batter into the prepared baking pan. In a small bowl, combine the sugar and cinnamon for the swirl. Sprinkle half of the cinnamon-sugar mixture evenly over the batter. Top with the remaining cake batter and then sprinkle with the remaining cinnamon-sugar mixture.
  7. Add Crumb Topping: Sprinkle the chilled crumb topping evenly over the cake.
  8. Bake: Bake in a preheated oven at 350°F (175°C) for 35-45 minutes, or until a toothpick inserted into the center comes out clean (or with just a few moist crumbs attached).
  9. Cool: Let the cake cool in the pan for 10-15 minutes before slicing and serving.