Heat oven to 375 degrees F. Grease large muffin tin (6 muffins)

In bowl, mix together flour, baking soda, baking powder and cinnamon.

In another bowl (preferrably stand mixer bowl) beat together with paddle attachment the sugar and butter until pale and fluffy, about 4-5 minutes. Beat in eggs, one at a time, and then the vanilla extract.

Add half the flour mixture to the butter mixture and beat until combined. Add sour cream and the milk; continue to beat until combined. The last addition should be the remaining flour. Beat until combined. The batter should be on the thick side.

In small bowl combine 1/4 cup cup sugar with cinnamon and blend.

Spoon batter into muffin tin to 3/4 of the way full; top with cinnamon and sugar (about a teaspoon).

Bake for 25 minutes, but check at 20 minutes.