Preheat oven to 350 degrees.
Spray 2 muffin tins with cooking spray, set aside
With a wooden spoon, beat together 2 cups sugar, butter and eggs
Add in buttermilk, flour, and baking soda and mix until fully incorporated
Using a little less than half the batter,place a spoonful of batter into each muffin cup.
In a medium sized separate bowl, stir together the ⅔ cup sugar and cinnamon.
Using approximately half this cinnamon sugar mixture, sprinkle over the batter in each muffin tin (Using approximately ½ to¾ teaspoon for each muffin).
Top each muffin with the remaining batter, filling the muffin tins ⅔ full
Sprinkle remaining cinnamon sugar mixture over top of each muffin tin
Using a butter knife, swirl each individualmuffin so that the cinnamon sugar mixture will be throughout each muffin.
Bake for approximately 25 to 30 minutes,until a toothpick inserted comes out clean.
Mix glaze ingredients while muffins arebaking.
Top with glaze while still warm.
Let cool in pan for a few minutes