Grate lemon zest directly onto the 1 cup total of sugar we need for the recipe and rub in with your fingertips to flavor the sugar with the lemon essential oils.
Add blueberries, lemon sugar and water to a medium sized pot and bring all to a simmer on medium heat. Reduce heat and let simmer for 30 - 45 minutes until you have an almost jam-like consistency.
Add spices and lemon juice and take pot off the heat.
Combine milk, sour cream and vanilla and stir. In a separate bowl, combine flour, baking powder, salt and 1/4 cup of lemon sugar. Grate cold butter on top of dry mix and combine. Alternatively, you can quickly pulse the dry mix and butter in the food processor. Add liquids and quickly combine to a shaggy batter. Don't stir too much or your drop biscuits will be tough.
Taking 1 tbsp of batter at a time, shape the batter to dumplings between 2 tbsp and place them on the blueberry jam in the pot. Place pot on medium heat and put a tight-fitting lid on. Simmer for 14 minutes and do not lift the lid during that time.
Serve with vanilla ice cream or sour cream.