Preheat oven to 350°F. Spray a 13x9 inch baking pan with cooking spray. Set aside.
In the bowl of a stand mixer fitted with the paddle attachment, cream the butter and sugars on medium speed for 2-3 minutes or until light and fluffy. Add the eggs, one at a time. Beating well after each addition. Scrape down the sides and bottom of the bowl. Add the vanilla bean paste, and mix to combine.
In a medium bowl whisk the flour, salt, baking powder, and baking soda.
With the mixer on low, alternate adding the dry ingredients with the sour cream, starting and ending with the dry ingredients. (Flour, sour cream, flour, sour cream, flour). Mix until just combined. Being sure to stop and scrape down the sides and bottom of the bowl as needed. Don’t overmix.
Pour half of the batter into the prepared pan. Sprinkle half of the cinnamon sugar mixture over the batter. Scoop the remaining cake batter over the cinnamon mixture. Carefully spread the batter to make an even layer (use an off set spatula to make it easier). Sprinkle remaining cinnamon sugar mixture over the top of the cake. Using a knife, gently swirl the cinnamon sugar mixture into the top layer of batter.
Bake cake for 43-46 minutes or until a toothpick inserted in the center of the cake comes out clean (mine baked for 45 minutes). Let the cake cool for a littel bit before glazing the cake.
Cinnamon Sugar Topping
In a small bowl combine the brown sugar and cinnamon.
Combine butter, powdered sugar, and vanilla in a bowl. Beat until combined. Slowly add in the milk a tablespoon at a time until it reaches a syrup-y like consistency. Drizzle over the cake once the cake has cooled slightly.
I like to pour the glaze over the cake after it has cooled for about 30-40 minutes. The cake is still just *barely* warm. But you can glaze the cake once it's fully cooled. Both work and taste great!