Combine all ingredients for the vanlla ginger syrup in a small saucepan. Bring to a boil over medium heat and boil for one minute. Remove from heat and allow to cool.
When ready to make the margarita take a lime wedge and rub it around the edge of a tall glass. Dip the glass into coarse salt. Fill glass with ice and set aside.
In a shaker combine the cranberry juice, lime juice, vanilla ginger simple syrup, orange liqueur, and tequila. Shake for 30 seconds.
Pour the margarita into the prepared glass. Top with sugared cranberries and the lime wedge.