- 2 cups all-purpose flour
- 1 1/2 cups granulated sugar
- 1/2 teaspoon baking soda
- 2 teaspoons baking powder
- 1/2 teaspoon salt
- 1 1/3 cups light or regular sour cream
- 2/3 cup butter, softened
- 1 teaspoon vanilla
- 3 large eggs
- 3/4 cup butter, softened
- 3/4 cup light brown sugar
- 1 tablespoon flour
- 1 tablespoon ground cinnamon
- 2 cups powdered sugar
- 4-5 tablespoons milk
- 1/2 teaspoon vanilla
- Preheat oven to 350 degrees F. Lightly grease a 9X13-inch baking pan with nonstick cooking spray and set aside.
- In a large bowl, combine all the cake batter ingredients and mix well. Spread the batter evenly in the prepared pan.
- In a small bowl, stir together the butter, light brown sugar, flour and cinnamon for the swirl mixture. The butter should be soft enough to make a smooth (but not soupy) mixture. Drop the cinnamon/butter mixture by tablespoons over the cake batter. Make sure to get a few dollops close to the edges (otherwise the cake bakes up and squeezes all the cinnamon sugar mixture to the middle).
- Using a butter knife, swirl the cinnamon mixture into the cake batter, reaching all the way to the edges and pulling in to create swirls from edge to edge. Don’t overswirl – just enough to create generous loops of cinnamon and sugar throughout the cake batter.
- Bake the cake for 30-32 minutes until a toothpick inserted in the center comes out clean or with a few moist crumbs.
- For the glaze, whisk together the powdered sugar, milk and vanilla until smooth. Pour evenly over the cake while it is still warm within 5-10 minutes of removing from the oven.
- Serve the cake warm or at room temperature (it can be reheated slightly as individual servings in the microwave and tastes just lovely warmed up like that).