Ingredients:
- 1/2 cup (100g) granulated sugar (for crumb topping)
- 1/4 cup (30g) all-purpose flour (for crumb topping)
- 1/4 teaspoon ground cinnamon (for crumb topping)
- 1/4 cup (57g) cold unsalted butter, cut into small cubes (for crumb topping)
- 1 1/2 cups (192g) all-purpose flour (for cake)
- 1 teaspoon baking powder (for cake)
- 1/2 teaspoon baking soda (for cake)
- 1/4 teaspoon salt (for cake)
- 1/2 cup (113g) unsalted butter, softened (for cake)
- 3/4 cup (150g) granulated sugar (for cake)
- 2 large eggs (for cake)
- 1 teaspoon vanilla extract (for cake)
- 1 cup (240ml) sour cream (full-fat preferred) (for cake)
Instructions:
- Preheat oven to 350°F (175°C). Grease and flour a 9-inch round cake pan or line with parchment paper.
- In a medium bowl, combine sugar, flour, and cinnamon (for crumb topping). Cut in the cold butter using a pastry blender or your fingertips until the mixture resembles coarse crumbs. Set aside in the fridge.
- In a separate bowl, whisk together flour, baking powder, baking soda, and salt (for cake).
- In a large bowl, cream together the softened butter and sugar (for cake) until light and fluffy.
- Beat in the eggs one at a time, then stir in the vanilla extract (for cake).
- Gradually add the dry ingredients to the wet ingredients, alternating with the sour cream, beginning and ending with the dry ingredients. Mix until just combined. Do not overmix.
- Pour the batter into the prepared cake pan. Sprinkle the crumb topping evenly over the batter.
- Bake for 45-55 minutes, or until a wooden skewer inserted into the center comes out clean.
- Let the cake cool in the pan for 10-15 minutes before transferring it to a wire rack to cool completely.