Preheat the oven to 350°F and line a standard muffin pan with paper liners.
In a small bowl combine the minced fresh ginger and granulated sugar, and let it sit until you are done with the muffin batter.
In a large bowl lightly beat the eggs. Add the sour cream, oil, and canned pumpkin and stir well. Mix in the brown sugar and vanilla. The batter will be frothy and kind of fluffy at this point.
Add the flour, cocoa, baking powder, ginger, cinnamon, baking soda, and salt.
Stir until just combined. Then fold in the chocolate chips and sweetened ginger.
Divide the batter evenly between the 12 prepared muffin cups.
Bake for 18 - 20 mins. Let them cool slightly before removing from the pan.