In a small bowl, mix 1/2 cup sugar and 1-1/2 TB cinnamon and set aside.
Preheat oven to 350 degrees F. Grease 2 muffin pans or line with paper baking cups.
In the bowl of a stand mixer, cream butter, 1 cup of sugar, brown sugar and vanilla. Cream for 3-5 minutes or until fluffy. Add the eggs one at a time, mixing after each one. Mix in sour cream and stir just until combined.
Add one tablespoon from the cinnamon sugar mixture.
In a separate bowl, whisk together flour, baking soda, baking powder, cream of tartar, and nutmeg.
Slowly add the flour mixture to the wet ingredients. Scrape down the bowl as needed. Fold in the cinnamon chips.
Place batter in the fridge for about 10-15 minutes.
Using an ice cream scoop, scoop the batter into the cinnamon-sugar mixture and roll around to coat completely, making sure not to press your fingers into the batter while you roll. Place the coated muffins into the prepared tins.
Bake for 17-20 minutes (17 with no liners, 20 with liners), or until golden brown and a toothpick inserted in the center comes out clean. Remove from the oven and let cool in the pans for 5 minutes before removing them to a wire rack to cool completely.
For the glaze:
Melt butter in a saucepan. Stir in maple syrup. Add powdered sugar and vanilla – it will be thick and sticky. Add water until desired consistency is reached.
Drizzle the glaze over the warm muffins with a spoon or a fork.