In a cocktail shaker, add the spiced cranberry simple syrup, gin and lemon juice along with a handful of ice.
Put on the top and give it a good, vigorous shake to chill the mixture. About 15-30 seconds takes care of the job.
After shaking, remove the top from the cocktail shaker and strain the chilled cranberry mixture into a Champagne flute.
Now pop off that Champagne cork. Top the flute with that delightfully bubbly Champagne -- and that's it!