2 1/2 cups all-purpose flour

2 teaspoons baking powder

1 teaspoon cream of tartar

1/2 teaspoon baking soda

1/2 teaspoon salt

1 cup unsalted butter, softened

1 3/4 cups granulated sugar

4 large eggs, room temperature

1 cup sour cream, room temperature

2 teaspoons vanilla extract

1/2 cup whole milk or buttermilk

1/3 cup granulated sugar (for swirl)

2 tablespoons ground cinnamon (for swirl)

2 tablespoons melted butter (for swirl)

1 cup unsalted butter, softened (for buttercream)

8 oz cream cheese, softened

5 cups powdered sugar, sifted

2 teaspoons vanilla extract (for buttercream)

1 1/2 teaspoons ground cinnamon (for buttercream)

3–4 tablespoons heavy cream

Pinch of salt

2 tablespoons cinnamon sugar (for topping)