Preheat the oven to 350°F.

Spray a bundt cake pan liberally with nonstick cooking spray. Set aside.

Place the butter, sugar, and vanilla into a large mixing bowl. Using a hand mixer or stand mixer fitted with a whisk attachment, cream the ingredients together on medium speed for 1 minute, or until smooth. Add the eggs and sour cream, and continue to beat for a minute more, until the mixture is light and fluffy.

Sift the flour, baking powder, baking soda, and salt into the bowl. Beat the mixture on low, scraping down the sides of the bowl with a rubber spatula as needed, until a smooth, medium-thick batter forms.

In a small bowl, whisk together the brown sugar, cinnamon, and salt until thoroughly combined.

Spread 1/3 of the cake batter into the bundt pan. Sprinkle half the cinnamon sugar mixture evenly on top. Layer another 1/3 of the batter into the pan, and evenly sprinkle over the remaining cinnamon sugar. Top with the remaining batter.

Bake the bundt cake on the middle rack of oven until a toothpick inserted in the center of the cake comes out clean, 55-70 minutes.

Check to see that cake is done. Remove from oven or add time as needed.

Allow the cake to cool in the pan for 15-20 minutes. To release the cake, run a butter knife between the edge of the cake and the pan. Turn the cake onto a large serving plate.

Allow the cake to cool for 1-2 hours before slicing and serving.