the sour cream. stir until well combined.
mix together flour, baking soda and 1 teaspoon of cinnamon. add to the wet mix.
fold in rhubarb just until mixed.
spray muffin tins with pam. fill tins to the top.
mix the remaining cinnamon and white sugar. sprinkle on muffins.
these look delicious. i will be baking these as soon as i can get some rhubarb. 