Cinnamon Roll Muffin

1 C (2 sticks) butter, room temperature
2 C sugar
2 eggs
2 C buttermilk
4 C all-purpose flour
2 tsp baking soda

Cinnamon Sugar Mix:
2/3 C sugar
2 tsp cinnamon

Glaze:
2 C confectioners' sugar
2 T butter, softened
1 tsp vanilla
1 T orange juice

Preheat oven to 350 degrees.  Spray two 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 2/3 cup sugar and cinnamon.  Using approximately half this cinnamon sugar mixture, sprinkle over the batter in each muffin tin (Using approximately 1/2 to 3/4 tsp for each muffin).  Top each muffin with the remaining batter, filling the muffin tins 2/3 full.  Sprinkle remaining cinnamon sugar mixture over top of each muffin tin.  Using a butter knife, swirl each individual muffin 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 are baking.  Top with glaze while still warm.  Let cool in pan for a few minutes.