Combine the cranberries, sugar, and water in a small saucepan over medium heat.
Bring the mixture to a gentle simmer, allowing the cranberries to soften and burst, releasing their juice—this takes about 5 minutes and fills your kitchen with a fruity aroma.
Gently crush the cranberries with the back of a spoon or muddler to help release more juice, then simmer for another 10 minutes, stirring occasionally.
Strain the syrup through a fine sieve into a bowl, pressing gently to extract all the vibrant red juice. Discard the solids and let the syrup cool completely.
Pour about 2 tablespoons of the chilled cranberry syrup into each flute or tall glass.
Gently top each glass with chilled sparkling wine, pouring slowly to preserve the bubbles and create a lively fizz.
Garnish each drink with a twist of orange peel and a few fresh cranberries for a festive and colorful touch.
Serve immediately and enjoy the crisp, tart sparkle of this bright winter cocktail.