Combine the blueberries, sweetener and water in a small blender and blend until smooth. Pour the blueberry juice through a fine strainer and press through. Discard the skins and seeds. Store the blueberry juice in the refrigerator or freezer until ready to use. Combine the blueberry juice, vodka, and lime juice in a cocktail shaker with four ice cubes. Shake for 10 seconds. Add the ginger beer and mix with a spoon - don't shake or it will lose it's carbonation. On a small plate, stir together the sweetener and cinnamon and spread out. Drag a wedge of lime around the rim of your glass to moisten. Dip rim of glass in cinnamon mixture and lift carefully. Add ice to your glass and pour the cocktail into it. Garnish with lime and fresh blueberries if desired.