sadly, I did a little bit of this today
just 89 days left...not that I'm counting ;)
Preheat oven to 180C. Line a muffin pan with paper cases.
Mix the 2/3 cup extra sugar with cinnamon and set aside.
In a separate bowl, cream the butter and sugar. Mix in the eggs and vanilla.
Add the sour cream and buttermilk and mix well. Stir in the dry ingredients and mix until smooth.
Using a spoon, drop a scoop of the batter into the cinnamon sugar bowl. Gently roll the batter in the mixture. Place the ball into the muffin paper case.
Sprinkle any remainder cinnamon sugar on top of the muffins and bake for 15 minutes or until a skewer inserted in the centre comes out clean.