Preheat oven to 350° F. Lightly spray a 10" tube pan with non-stick cooking spray and set aside.
In the bowl of a stand mixer, cream butter and 2 cups of the sugar on medium to medium-high speed until light fluffy, about 3 minutes. Add eggs, one at a time, beating well after each addition. Then beat in vanilla.
In a small bowl, combine flour, baking soda, and salt. Add to the butter and sugar mixture, alternating with sour cream, beating just enough after each addition to keep batter smooth.
With a spatula, transfer a third of the batter into prepared tube pan and level it out.
In a small bowl, combine cinnamon and remaining ¾ cup of sugar, and sprinkle a third of this cinnamon sugar mixture over batter in pan. Repeat layers two more times, alternating batter and cinnamon sugar, ending with a layer of cinnamon sugar on top.
Bake for 60 to 65 minutes, or until a toothpick inserted in the center just comes out clean.
Cool for 30 to 45 minutes. Then cut around the pan edges with a knife and remove cake from pan to a wire rack to cool completely.
