Grease and flour a bundt pan well. Preheat the oven to 325 degrees.

In a mixing bowl, combine the flour, baking powder, salt and ¼ teaspoon of cinnamon. Whisk well and set aside.

In another bowl, add the sour cream, milk and vanilla. Whisk well and set aside.

In a large mixing bowl, add the butter and 1 ¾ cup of regular sugar. Mix on medium and then on medium high for several minutes until light and fluffy.

Add in the eggs two at a time and mix on medium just until combined.

Alternately add in the flour mixture and the sour cream mixture. (Add in ⅓ of the flour mixture and mix on medium just until combined. Add in ½ the sour cream mixture, mixing only until combined. Add in another ⅓ of the flour mixture, mixing only until combined. Add in the last of the sour cream mixture, mixing only until combined, then the last of the flour mixture and mix until well combined.) You only want to mix until well combined, about 20 seconds. Mixing for several minutes is too long.

In another bowl, mix together ½ cup packed brown sugar and 2 tablespoon of cinnamon and set aside.

Add a little less than ½ of the cake batter to your pan and smooth.

Sprinkle the sugar, cinnamon mixture over the batter.

Add the remaining cake batter into the pan and smooth.

Bake at 325 degrees for about 55 minutes to 1 hour.

In a mixing bowl, add in the confectioners sugar, cinnamon, extract and milk. Mix well until smooth. Check the consistency. If it's too thick for drizzling, add more milk or cream by tablespoon until desired consistency.

Drizzle over cooled cake.