In a sauce pan, stir together all of the syrup ingredients. Bring to a boil over medium high heat. Once mixture starts to boil, reduce heat to medium or medium low and simmer for 10 - 15 minutes, stirring occasionally.
Let mixture cool. Use a blender or immersion blender to blend syrup mixture, along with 1/4 cup of water, until mixture is pureed. Pour mixture through a fine mesh strainer and strain into an air tight container. Store in refrigerator until ready to use.
Prepare margaritas by adding the cinnamon and sugar to plate and mixing together. Wet the rim of two cocktail glasses with lime juice and rub the rim in the sugar mixture until the entire rim of glass is coated with cinnamon sugar. Fill glass with ice a little over half way.
In a cocktail shaker, add cranberry syrup, tequila, triple sec and lime juice. Shake and pour into prepared cocktail glasses. Garnish with fresh cranberries and limes if you like. Serve immediately.
Notes
Cranberry syrup will last in refrigerator in an airtight container for up to 2 weeks.