# What You Need:
→ Cake
01 - 2 cups all-purpose flour
02 - 1 cup granulated sugar
03 - 1/2 cup unsalted butter, softened
04 - 1 cup sour cream
05 - 2 large eggs
06 - 1 teaspoon vanilla extract
07 - 1 teaspoon baking powder
08 - 1/2 teaspoon baking soda
09 - 1/4 teaspoon salt
→ Cinnamon Swirl
10 - 1/2 cup packed brown sugar
11 - 2 teaspoons ground cinnamon
→ Streusel Topping
12 - 1/2 cup all-purpose flour
13 - 1/3 cup packed brown sugar
14 - 1/2 teaspoon ground cinnamon
15 - 1/4 cup unsalted butter, melted
# How To Make:
01 - Preheat oven to 350°F. Grease a 9-inch square baking pan or line with parchment paper.
02 - Whisk together flour, baking powder, baking soda, and salt in a medium bowl; set aside.
03 - Beat softened butter and granulated sugar in a large bowl until light and fluffy. Add eggs one at a time, mixing well after each, then incorporate vanilla extract.
04 - Mix in sour cream until smooth. Gradually add dry ingredients, stirring just until combined; do not overmix.
05 - Combine brown sugar and cinnamon in a small bowl.
06 - Spread half of the batter evenly in the prepared pan. Sprinkle cinnamon-sugar mixture over the batter. Top with remaining batter and gently spread to cover.
07 - Mix flour, brown sugar, and cinnamon for streusel in a bowl. Stir in melted butter until crumbly. Sprinkle streusel evenly over the batter.
08 - Bake for 38 to 42 minutes or until a toothpick inserted into the center comes out clean.
09 - Allow cake to cool in the pan for at least 20 minutes before slicing.
